config: remove the pkgconfig pc.in file from EXTRA_DIST

Automake always includes it in the tarball.

Signed-off-by: Gaetan Nadon <memsize@videotron.ca>

Makefile.am

@@ -25,7 +25,6 @@ pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = xcomposite.pc
 
 MAINTAINERCLEANFILES = ChangeLog INSTALL
-EXTRA_DIST = xcomposite.pc.in 
 
 .PHONY: ChangeLog INSTALL