Just `memset()` this to `0`.

Without this kamailio segfaults when running `fparam_free_restore()` on a variable that contains transformations immediately after creation, because field `next` of the transformation contains garbage.

In my case this was variable which contained `re.subst` transformation. And below is the top of the backtrace.

``` #0 0x00000000005cba17 in tr_param_free (tp=0x292873257325203a) at core/pvapi.c:1804 #1 0x00000000005cb677 in tr_destroy (t=0x7f6387ed0c40) at core/pvapi.c:1742 #2 0x00000000005cb9c1 in tr_free (t=0x0) at core/pvapi.c:1786 #3 0x00000000005ca194 in pv_spec_destroy (spec=0x7f6387ed0b80) at core/pvapi.c:1570 #4 0x00000000005ca1b7 in pv_spec_free (spec=0x7f6387ed0b80) at core/pvapi.c:1578 #5 0x0000000000541820 in fparam_free_contents (fp=0x7f6387ed0ae0) at core/sr_module.c:1334 #6 0x0000000000541898 in fparam_free_restore (param=0x7f6387ed1168) at core/sr_module.c:1364 ```

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You can view, comment on, or merge this pull request online at:

https://github.com/kamailio/kamailio/pull/1506

-- Commit Summary --

* properly initialize new tr_param_t object

-- File Changes --

M src/modules/textops/txt_var.c (1)

-- Patch Links --

https://github.com/kamailio/kamailio/pull/1506.patch https://github.com/kamailio/kamailio/pull/1506.diff