clean before build

tools/make-chromium.sh

@@ -4,9 +4,11 @@
 
 echo "*** µMatrix(Chromium): Creating package"
 echo "*** µMatrix(Chromium): Copying files"
-mkdir -p ./dist/uMatrix.chromium
-cp -R ./src/*           ./dist/uMatrix.chromium/
-cp -R ./tools/_locales  ./dist/uMatrix.chromium/
-cp -R ./assets          ./dist/uMatrix.chromium/
-cp    ./meta/chromium/* ./dist/uMatrix.chromium/
+DES=./dist/uMatrix.chromium
+rm -rf $DES
+mkdir -p $DES
+cp -R ./src/*           $DES
+cp -R ./tools/_locales  $DES
+cp -R ./assets          $DES
+cp    ./meta/chromium/* $DES
 echo "*** µMatrix(Chromium): Package done."