[gimp] configure: fix linking with ExcHndl for Dr. MinGW.

[Jehan Pagès <jehanp src gnome org>]

commit 500589e97c171e24498cfd5a4250bed99b92ae31
Author: Jehan <jehan girinstud io>
Date:   Sun Jun 12 04:18:30 2016 +0200

    configure: fix linking with ExcHndl for Dr. MinGW.

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index fcb9416..36d0999 100644
--- a/configure.ac
+++ b/configure.ac
@@ -819,6 +819,7 @@ if test "x$platform_win32" = "xyes"; then
    AC_CHECK_LIB(exchndl, ExcHndlSetLogFileNameA,
                 [
                  AC_DEFINE(HAVE_EXCHNDL, 1, [Define to 1 when Dr. MingW is available])
+                 LIBS="-lexchndl $LIBS"
                  enable_drmingw="yes"
                 ],
                 [enable_drmingw="no (ExcHndl library missing)"]