Remove advanced setting `ignoreScriptInjectFilters`

Ever since the `redirect` code was refactored:

157cef6034

This advanced setting is no longer needed, as the same
can be accomplished with a plain network filter:

    @@*$redirect-rule

src/js/background.js

@@ -63,7 +63,6 @@ const µBlock = (( ) => { // jshint ignore:line
         extensionUpdateForceReload: false,
         filterAuthorMode: false,
         filterOnHeaders: false,
-        ignoreRedirectFilters: false,
         ignoreScriptInjectFilters: false,
         loggerPopupType: 'popup',
         manualUpdateAssetFetchPeriod: 500,

src/js/pagestore.js

@@ -821,7 +821,6 @@ const PageStore = class {
     }
 
     redirectBlockedRequest(fctxt) {
-        if ( µb.hiddenSettings.ignoreRedirectFilters === true ) { return; }
         const directives = µb.staticNetFilteringEngine.redirectRequest(fctxt);
         if ( directives === undefined ) { return; }
         if ( µb.logger.enabled !== true ) { return; }