Don't exit if misbehaving libraries are not found

- When creating an AppImage, certain libraries must be removed
- The script will currently exit when it fails to delete such a library
- The script should not exit if such a library was never present

support/linux_AppDir_create.sh

@@ -146,6 +146,9 @@ fi
 
 # Manually add and remove libraries which don't behave appropriately.
 
+# Some libraries may not be present. If they are not present, continue processing.
+set +e
+
 rm $APP_DIR/lib/ld-linux*
 rm $APP_DIR/lib/libc.so*
 rm $APP_DIR/lib/libdl.so*
@@ -158,5 +161,8 @@ rm $APP_DIR/lib/librt.so*
 rm $APP_DIR/lib/librtmp.so*
 rm $APP_DIR/lib/libX11.so*
 
+# Resume exit-on-fail behavior.
+set -e
+
 cp -d $PREFIX/lib/libCEGUI* $APP_DIR/lib
 cp -r $PREFIX/lib/cegui* $APP_DIR/lib