PLT-3237 Update displayed config values in admin console after saving (#3506)

* Reloaded admin console data when settings are saved

* Fixed attempting to save an invalid config setting overwriting the stored config

webapp/components/admin_console/email_authentication_settings.jsx

@@ -15,12 +15,6 @@ export default class EmailAuthenticationSettings extends AdminSettings {
         this.getConfigFromState = this.getConfigFromState.bind(this);
 
         this.renderSettings = this.renderSettings.bind(this);
-
-        this.state = Object.assign(this.state, {
-            enableSignUpWithEmail: props.config.EmailSettings.EnableSignUpWithEmail,
-            enableSignInWithEmail: props.config.EmailSettings.EnableSignInWithEmail,
-            enableSignInWithUsername: props.config.EmailSettings.EnableSignInWithUsername
-        });
     }
 
     getConfigFromState(config) {
@@ -31,6 +25,14 @@ export default class EmailAuthenticationSettings extends AdminSettings {
         return config;
     }
 
+    getStateFromConfig(config) {
+        return {
+            enableSignUpWithEmail: config.EmailSettings.EnableSignUpWithEmail,
+            enableSignInWithEmail: config.EmailSettings.EnableSignInWithEmail,
+            enableSignInWithUsername: config.EmailSettings.EnableSignInWithUsername
+        };
+    }
+
     renderTitle() {
         return (
             <h3>