gnucash: changed to not remove -Werror through gcc wrapper (see note!)

Note:

gnucash builds fine now, even with -Werror enabled, so I removed the
workaround. Besides that I added the official configure option
'--disable-error-on-warning' but left it commented.

office/gnucash/gnucash.conf

@@ -17,5 +17,5 @@
 # workaround autoconf error: possibly undefined macro: AM_GCONF_SOURCE_2
 hook_add preconf 9 "autoreconf -v -I $(pkgprefix -r datadir gconf)/aclocal"
 
-var_append GCC_WRAPPER_REMOVE " " "-Werror"
-
+# disable treating compile warnings as errors
+# var_append extraconfopt ' ' '--disable-error-on-warning'