[gegl] Bug 740582 - Not all shells support the += syntax

[Michael Natterer <mitch src gnome org>]

commit 4717b19118eb124a2d8d53497f5e8d587b6e4cc9
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Mon Nov 24 00:39:59 2014 +0800

    Bug 740582 - Not all shells support the += syntax
    
    configure: support shells which do not recognize the += syntax.

 configure.ac |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 97d946a..2bbfc4e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -497,10 +497,10 @@ GLIB_PACKAGES="gobject-2.0 gmodule-2.0 gio-2.0"
 # select platform-specific GIO
 case "$os_win32" in
   yes)
-    GLIB_PACKAGES+=" gio-windows-2.0"
+    GLIB_PACKAGES="$GLIB_PACKAGES gio-windows-2.0"
     ;;
   *)
-    GLIB_PACKAGES+=" gio-unix-2.0"
+    GLIB_PACKAGES="$GLIB_PACKAGES gio-unix-2.0"
     ;;
 esac