fix(client) remove dead code to render avatars

The scheduled meeting view doesn't render participant avatars, so kill
all supporting code.

spot-client/src/common/app-state/config/default-config.js

@@ -43,15 +43,6 @@ export default {
         PUSH_NOTIFICATIONS_ENABLED: process.env.CALENDAR_PUSH_NOTIFICATIONS_ENABLED === 'true'
     },
 
-    /**
-     * The avatar image to display in the meetings list when a participant of
-     * the meeting has no gravatar configured.
-     *
-     * @type {string}
-     */
-    DEFAULT_AVATAR_URL: process.env.DEFAULT_AVATAR_URL
-        || `https://${DEFAULT_DOMAIN}/images/avatar.png`,
-
     /**
      * The app background image to display. By default a solid color is
      * displayed as the background.

spot-client/src/common/app-state/config/selectors.js

@@ -52,17 +52,6 @@ export function getCalendarConfig(state) {
     return state.config.CALENDARS;
 }
 
-/**
-* A selector which returns the configured default avatar URL to display for
-* people without avatar URLs.
-*
-* @param {Object} state - The Redux state.
-* @returns {string}
-*/
-export function getDefaultAvatarUrl(state) {
-    return state.config.DEFAULT_AVATAR_URL;
-}
-
 /**
 * A selector which returns which Jitsi-Meet deployment domain to direct
 * meetings to which do not specify a domain.

spot-client/src/common/ui/components/scheduled-meetings/scheduled-meeting.js

@@ -6,7 +6,6 @@ import { withTranslation } from 'react-i18next';
 
 
 import { Button } from './../button';
-import Avatar from './avatar';
 
 /**
  * Displays details about a meeting and response to clicks.
@@ -78,23 +77,6 @@ export class ScheduledMeeting extends React.Component {
         );
     }
 
-    /**
-     * Creates a React Element for each meeting participant for displaying that
-     * participant's avatar.
-     *
-     * @param {Array<Object>} participants - The event participants to display
-     * as avatars.
-     * @private
-     * @returns {Array<ReactElement>}
-     */
-    _generateAvatars(participants = []) {
-        return participants.map(participant => (
-            <Avatar
-                email = { participant.email }
-                key = { participant.email } />
-        ));
-    }
-
     /**
      * Returns the calendar date for the meeting.
      *