fix header dependencies

The wildcard dependency in prepare doesn't work (at least not with GNU make 3.82):

```
make[1]: Entering directory `/home/bene/projects/remerge/aerospike-client-c/modules/mod-lua'
make[1]: *** No rule to make target `target/Linux-x86_64/include/aerospike/*.h', needed by `prepare'.  Stop.
make[1]: Leaving directory `/home/bene/projects/remerge/aerospike-client-c/modules/mod-lua'
make: *** [MOD_LUA-make-prepare] Error 2
```

This patch fixes the issue.