[gimp] configure: add a "Eeeeeeeeeeeeeeeeeeeeek" notice on configure error.

[Jehan Pagès <jehanp src gnome org>]

commit b2a44a90a77c2a2624f8f5803d1d65dd37438de2
Author: Jehan <jehan girinstud io>
Date:   Thu Feb 2 01:18:43 2017 +0100

    configure: add a "Eeeeeeeeeeeeeeeeeeeeek" notice on configure error.
    
    This makes it easier to search in config.log and should make Mitch
    happy (or at least happier!).

 configure.ac |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index e84c1d1..65ff74d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -632,6 +632,7 @@ required_deps=''
 # If details about the dependency are needed:
 # add_deps_error([dependency], [first line, second line])
 m4_define([add_deps_error], [
+  AC_MSG_NOTICE([Eeeeeeeeeeeeeeeeeeeeek! Missing dep: $1])
   required_deps="$required_deps
   - Error: missing dependency $1"
   m4_foreach([more], [$2], [