Ico files support compression

Author: LeoColomb

h5bp/web_performance/compression.conf

@@ -46,6 +46,7 @@
                                       "image/bmp" \
                                       "image/svg+xml" \
                                       "image/vnd.microsoft.icon" \
+                                      "image/x-icon" \
                                       "text/cache-manifest" \
                                       "text/calendar" \
                                       "text/css" \