[gimp] tools: add invert-svg in the DISTCLEANFILES.

[Jehan Pagès <jehanp src gnome org>]

commit b8a04c5a0817d1faacac9cffac179f3396c9eb43
Author: Jehan <jehan girinstud io>
Date:   Wed Mar 29 19:59:10 2017 +0200

    tools: add invert-svg in the DISTCLEANFILES.
    
    Since the build executable is not compiled the usual *_PROGRAMS way,
    automake does not know to delete it. Add it specifically.

 tools/Makefile.am |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/tools/Makefile.am b/tools/Makefile.am
index 73d9cb4..897d603 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -91,3 +91,5 @@ EXTRA_DIST = \
 
 # Build tools which must be built for the host platform.
 all: invert-svg$(BUILD_EXEEXT)
+
+DISTCLEANFILES = invert-svg$(BUILD_EXEEXT)