ONOS-4359: continued work on theming UI (app control buttons).

Change-Id: I87c510caee499a2ecaa51241785e300cb06c1f61
(cherry picked from commit a705605)
diff --git a/web/gui/src/main/webapp/app/fw/svg/icon.css b/web/gui/src/main/webapp/app/fw/svg/icon.css
index bf9d28c..c665a1a 100644
--- a/web/gui/src/main/webapp/app/fw/svg/icon.css
+++ b/web/gui/src/main/webapp/app/fw/svg/icon.css
@@ -41,5 +41,5 @@
 }
 
 svg.embeddedIcon .icon.appInactive .glyph {
-    fill: none;
+    fill: none !important;
 }