When running "make swigclean" in mod_lua directory and trying to compile
mod_lua afterward, the build fails because the target mod_lua_wrap.cpp
doesn't exist. The target is wrongly called lua_wrap instead.

making all mod_lua
make[7]: Entering directory '/path/to/freeswitch-1.6.17/src/mod/languages/mod_lua'
  CXX mod_lua_la-mod_lua.lo
  CXX mod_lua_la-freeswitch_lua.lo
make[7]: *** No rule to make target 'mod_lua_wrap.cpp', needed by 'mod_lua_la-mod_lua_wrap.lo'. Stop.

Fix this by renaming lua_wrap to mod_lua_wrap.cpp.
Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>