[gimp-help/gimp-help-2-10] autogen.sh: tell aclocal where our custom m4 files are.

[Jacob Boerema <jboerema src gnome org>]

commit 2d152e733fd70d50836494182076467fe9a84163
Author: Jehan <jehan girinstud io>
Date:   Mon Aug 2 22:55:28 2021 +0200

    autogen.sh: tell aclocal where our custom m4 files are.

 autogen.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/autogen.sh b/autogen.sh
index 4c0073531..751c6a7a3 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -91,7 +91,7 @@ if test -z "$ACLOCAL_FLAGS"; then
     done
 fi
 
-$ACLOCAL $ACLOCAL_FLAGS
+$ACLOCAL -I m4macros $ACLOCAL_FLAGS
 RC=$?
 if test $RC -ne 0; then
    echo "$ACLOCAL gave errors. Please fix the error conditions and try again."