[MD settings] correct category for SUBRESOURCE_FILTER

This CL changes the SUBRESOURCE_FITER which is not a valid category
type to SUBRESOURCE_FILTER which is valid.

BUG=716661
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2851933002
Cr-Commit-Position: refs/heads/master@{#468426}

chrome/browser/resources/settings/privacy_page/privacy_page.html

@@ -410,7 +410,7 @@
               toggle-on-label="$i18n{siteSettingsSubresourceFilterBlock}">
           </category-default-setting>
           <category-setting-exceptions
-              category="{{ContentSettingsTypes.SUBRESOURCE_FITER}}">
+              category="{{ContentSettingsTypes.SUBRESOURCE_FILTER}}">
           </category-setting-exceptions>
         </settings-subpage>
      </template>