[sr-dev] fixup crash

i build sip proxy from latest master and got this kind of crash during startup:

(gdb) where #0 0x00297265 in ?? () #1 0x080961fd in fixup_free_pvar_all (param=0x297265, param_no=1) at mod_fix.c:307 #2 0x080bb035 in fix_actions (a=0x82d4de8) at route.c:956 #3 0x080d0f8b in fix_rval_expr (p=0x82d7608) at rvalue.c:3719 #4 0x080bb1b6 in fix_actions (a=0x82d1520) at route.c:750 #5 0x080bb635 in fix_actions (a=0x8274870) at route.c:754 #6 0x080bd869 in fix_rl (rt=0x82541f8) at route.c:2096 #7 0x080bd890 in fix_rls () at route.c:2112 #8 0x08092839 in main (argc=15, argv=0xbfd731b4) at main.c:2430

-- juha