Don't run zeromq/configure on external/Makefile.

This is already run when ./configure is run.

mythtv/external/Makefile

@@ -26,11 +26,6 @@ FFmpeg-all FFmpeg-install FFmpeg-uninstall FFmpeg-clean FFmpeg-distclean:
 zeromq-all:	zeromq/Makefile
 	${MAKE} -C zeromq all
 
-zeromq/Makefile:	zeromq/configure
-	(cd zeromq ; \
-	 ./configure --without-documentation --prefix=${PREFIX} \
-	             --includedir=${PREFIX}/include/mythtv/zeromq)
-
 zeromq-install zeromq-uninstall zeromq-clean zeromq-distclean:
 	${MAKE} -C zeromq ${@:zeromq-%=%} DESTDIR=${INSTALL_ROOT}