Dark theme: change loading spinner color

Now the loading spinner matches the blue color used by the rest of the
UI.

Change-Id: Id6847d2231dc13091fcf34bd85e4783d4fcc17d9
diff --git a/src/injections/ccdarktheme.css b/src/injections/ccdarktheme.css
index ad91c05..6857eb8 100644
--- a/src/injections/ccdarktheme.css
+++ b/src/injections/ccdarktheme.css
@@ -952,6 +952,11 @@
   color: var(--TWPT-primary-text)!important;
 }
 
+/* Loading spinner */
+material-spinner {
+  border-color: var(--TWPT-blue-A100)!important;
+}
+
 /* Custom injected components */
 .TWPT-log {
   background-color: #424242!important;