[sr-dev] [kamailio/kamailio] cfg_rpc updates changing variable values to large random numbers (#1583)

[vinesinha]

Turns out the `pragma` fix was just co-incidental. 
I did a couple of other tests. 
This time I printed the complete memory mapping as follows in `cfg_clone_global`:

```
LOG(L_ERR,"START");
LOG(L_ERR,"block address: %p",(void *)block);
LOG(L_ERR,"vars address: %p",(void *)(block->vars));
LOG(L_ERR,"Total allocated size: %d",(sizeof(cfg_block_t)+cfg_block_size-1));
int count = 0;
for (group = cfg_group;
	group;
	group=group->next
){
	count = count + 1;
	LOG(L_ERR,"Group number: %d", count);
	LOG(L_ERR,"Group location from start %d",(int)(((void *)(CFG_GROUP_DATA(block, group)))-((void *)block)));
	LOG(L_ERR,"Group size: %d", group->size);
}
```

I did two tests:
Test 1: With pragma block around cfg_block_t only
Test 2: With the complete patch applied 

Test1 output:

```
Memory mapping (with pragma for cfg_block_t)
============================================

(Error persists and variables takes random values)

## All the locations below assume that the address starts at 0

START
block address: 0x7f6c37550d98
vars address: 0x7f6c37550d9c
Total allocated size: 1160
Group number: 1
Group location from start 20
Group size: 248
Group number: 2
Group location from start 284
Group size: 56
Group number: 3
Group location from start 356
Group size: 4
Group number: 4
Group location from start 380
Group size: 4
Group number: 5
Group location from start 404
Group size: 4
Group number: 6
Group location from start 428
Group size: 176
Group number: 7
Group location from start 620
Group size: 104
Group number: 8
Group location from start 740
Group size: 200
Group number: 9
Group location from start 956
Group size: 16
Group number: 10
Group location from start 988
Group size: 172

## still one extra byte
```

As you can see 988+172=1160 but the address is starting from 0 here so we should have assigned 1161 bytes of memory.

Test2 output:

```
Memory mapping (with the complete patch applied)
================================================

(Error persists and variables takes random values)

## All the locations below assume that the address starts at 0

START
block address: 0x7fc1537af4b8
vars address: 0x7fc1537af4bc
Total allocated size: 1160
Group number: 1
Group location from start 20
Group size: 248
Group number: 2
Group location from start 284
Group size: 56
Group number: 3
Group location from start 356
Group size: 4
Group number: 4
Group location from start 380
Group size: 4
Group number: 5
Group location from start 404
Group size: 4
Group number: 6
Group location from start 428
Group size: 176
Group number: 7
Group location from start 620
Group size: 104
Group number: 8
Group location from start 740
Group size: 200
Group number: 9
Group location from start 956
Group size: 16
Group number: 10
Group location from start 988
Group size: 172

## still one extra byte
```

Not sure why the first group starts from location 20 but I can say with confidence that using `pragma` blocks doesn't solve this issue. 

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