Bug 1254987 - Get the subconfigure working properly for mail/configure.in. r=glandium

--HG--
extra : amend_source : b6672cca44a5d18d141d3458a64ebb09e98903ed

build/autoconf/subconfigure.m4

@@ -9,7 +9,7 @@ define([AC_DEFUN], [define($1, [$2])])
 
 dnl AC_ARG_ENABLE(FEATURE, HELP-STRING, IF-TRUE[, IF-FALSE])
 dnl We have to ignore the help string due to how help works in autoconf...
-AC_DEFUN([AC_ARG_ENABLE],
+AC_DEFUN([MOZ_AC_ARG_ENABLE],
 [#] Check whether --enable-[$1] or --disable-[$1] was given.
 [if test "[${enable_]patsubst([$1], -, _)+set}" = set; then
   enableval="[$enable_]patsubst([$1], -, _)"