feat: Drops SHOW_JITSI_WATERMARK_FOR_GUESTS and SHOW_WATERMARK_FOR_GUESTS.

interface_config.js

     SHOW_JITSI_WATERMARK: true,
     SHOW_POWERED_BY: false,
     SHOW_PROMOTIONAL_CLOSE_PAGE: false,
-    SHOW_WATERMARK_FOR_GUESTS: true, // if watermark is disabled by default, it can be shown only for guests
 
     /*
      * If indicated some of the error dialogs may point to the support URL for

react/features/base/react/components/web/Watermarks.js

  * @returns {Props}
  */
 function _mapStateToProps(state, ownProps) {
-    const { isGuest } = state['features/base/jwt'];
     const {
         customizationReady,
         customizationFailed,
         DEFAULT_LOGO_URL,
         JITSI_WATERMARK_LINK,
         SHOW_JITSI_WATERMARK,
-        SHOW_JITSI_WATERMARK_FOR_GUESTS,
         filmStripOnly
     } = interfaceConfig;
     let _showJitsiWatermark = (!filmStripOnly
           && (customizationReady && !customizationFailed)
-          && (SHOW_JITSI_WATERMARK || (isGuest && SHOW_JITSI_WATERMARK_FOR_GUESTS)))
+          && SHOW_JITSI_WATERMARK)
     || !isValidRoom;
     let _logoUrl = logoImageUrl;
     let _logoLink = logoClickUrl;