openolat#6: changed custom lti parameter value length from 15 to 50 for

uuid like params

src/main/java/org/olat/course/nodes/basiclti/LTIConfigForm.java

@@ -447,7 +447,7 @@ public class LTIConfigForm extends FormBasicController {
 		}
 		pair.setUserPropsChoice(userPropsChoice);
 
-		TextElement valEl = uifactory.addTextElement("val_" + guid, null, 15, value, customParamLayout);
+		TextElement valEl = uifactory.addTextElement("val_" + guid, null, 50, value, customParamLayout);
 		valEl.setDisplaySize(16);
 		valEl.setVisible(!userprops);
 		pair.setValueEl(valEl);