ensure push.so is linked with libcurl properly
ensure push.so is linked with libcurl properly

It looks as if the push module was not actually linking against the libcurl
shared library without these additional flags being passed.

jreese/znc-push,omnidan/znc-push,tonyolag/znc-push,larsks/znc-push,dgw/znc-push,kedare/znc-push