Add translation for server timeout

in German and English translations

app/features/settings/components/ServerTimeoutField.js

@@ -77,7 +77,7 @@ class ServerTimeoutField extends Component<Props, State> {
             <Form onSubmit = { this._onServerTimeoutSubmit }>
                 <FieldTextStateless
                     invalidMessage
-                        = { 'Invalid Timeout' }
+                        = { t('settings.invalidServerTimeout') }
                     isInvalid = { !this.state.isValid }
                     isValidationHidden = { this.state.isValid }
                     label = { t('settings.serverTimeout') }

app/i18n/lang/de.json

@@ -32,6 +32,7 @@
 		"startWithAudioMuted": "Ohne Audio starten",
 		"startWithVideoMuted": "Ohne Video starten",
 		"invalidServer": "Falsche Server URL oder der Server unterstützt keine externe API",
+		"invalidServerTimeout": "Üngültiger Wert für die Server Wartezeit",
 		"serverUrl": "Server URL",
         "serverTimeout": "Server Timeout (in Sekunden)"
 	}

app/i18n/lang/en.json

@@ -32,6 +32,7 @@
 		"startWithAudioMuted": "Start with Audio muted",
 		"startWithVideoMuted": "Start with Video muted",
 		"invalidServer": "Invalid Server URL or external API not enabled",
+		"invalidServerTimeout": "Invalid value for Server Timeout",
 		"serverUrl": "Server URL",
 		"serverTimeout": "Server Timeout (in seconds)"
 	}