zm_startup_geoip: warning: implicit declaration of function

[shakaran]

I get this warning compiling in Ubuntu 15.10:

/home/myuser/geoip/geoip.c: In function ‘zm_startup_geoip’:
/home/myuser/geoip/geoip.c:158:2: warning: implicit declaration of function ‘_GeoIP_setup_dbfilename’ [-Wimplicit-function-declaration]
  _GeoIP_setup_dbfilename();
  ^