[patch] Fix build for chat/libpurple without Gnome

[Pierre Pronchery <khorben%defora.org@localhost>]

			Hi there,

I'd like to commit the patch attached here, which fixes building
chat/libpurple for me (with the "gnome" option explicitly disabled).
Please let me know if that's ok.

HTH,
-- 
khorben

Index: options.mk
===================================================================
RCS file: /cvsroot/pkgsrc/chat/libpurple/options.mk,v
retrieving revision 1.28
diff -p -u -r1.28 options.mk
--- options.mk	7 Dec 2014 08:45:59 -0000	1.28
+++ options.mk	17 Jun 2015 03:11:43 -0000
@@ -21,6 +21,7 @@ PLIST.gnome=		yes
 GCONF_SCHEMAS+=		purple.schemas
 .else
 CONFIGURE_ARGS+=	--disable-schemas-install
+CONFIGURE_ENV+=		ac_cv_path_GCONFTOOL="no"
 .endif
 
 .if !empty(PKG_OPTIONS:Mgnutls)