Bug 1257448 - Don't disable MOZ_MEMORY when building fennec with --disable-compile-environment. r=nalexander

This was added in bug 1159371 but doesn't seem necessary anymore.

old-configure.in

@@ -2801,9 +2801,7 @@ case "${target}" in
         NSS_DISABLE_DBM=1
         MOZ_THEME_FASTSTRIPE=1
         MOZ_TREE_FREETYPE=1
-        if test "$COMPILE_ENVIRONMENT"; then
-            MOZ_MEMORY=1
-        fi
+        MOZ_MEMORY=1
         MOZ_RAW=1
         ;;