Fix issue #4291 : "Bug when edit current image in external editor"

Is also add metadata to the "ICC Reference image" (ICM tool).

rtengine/improccoordinator.cc

@@ -1284,6 +1284,8 @@ void ImProcCoordinator::saveInputICCReference (const Glib::ustring& fname, bool
         im = tempImage;
     }
 
+    im->setMetadata (imgsrc->getMetaData()->getRootExifData ());
+
     im->saveTIFF (fname, 16, true);
     delete im;