fix: clean default system error messages (#12951) (#12974)

Fixes #12939

Co-authored-by: caalador <mikael.grankvist@vaadin.com>

Author: vaadin-bot

flow-server/src/main/java/com/vaadin/flow/server/SystemMessages.java

@@ -31,21 +31,19 @@
  * <li><b>sessionExpiredURL</b> = null</li>
  * <li><b>sessionExpiredNotificationEnabled</b> = false</li>
  * <li><b>sessionExpiredCaption</b> = "Session Expired"</li>
- * <li><b>sessionExpiredMessage</b> = "Take note of any unsaved data, and
- * <u>click here</u> or press ESC key to continue."</li>
+ * <li><b>sessionExpiredMessage</b> = "Take note of any unsaved data, and click
+ * here or press ESC key to continue."</li>
  * <li><b>internalErrorURL</b> = null</li>
  * <li><b>internalErrorNotificationEnabled</b> = true</li>
  * <li><b>internalErrorCaption</b> = "Internal error"</li>
- * <li><b>internalErrorMessage</b> = "Please notify the administrator.<br>
- * Take note of any unsaved data, and <u>click here</u> or press ESC to
- * continue."</li>
+ * <li><b>internalErrorMessage</b> = "Please notify the administrator. Take note
+ * of any unsaved data, and click here or press ESC to continue."</li>
  * <li><b>cookiesDisabledURL</b> = null</li>
  * <li><b>cookiesDisabledNotificationEnabled</b> = true</li>
  * <li><b>cookiesDisabledCaption</b> = "Cookies disabled"</li>
  * <li><b>cookiesDisabledMessage</b> = "This application requires cookies to
- * function.<br>
- * Please enable cookies in your browser and <u>click here</u> or press ESC to
- * try again.</li>
+ * function. Please enable cookies in your browser and click here or press ESC
+ * to try again.</li>
  * </ul>
  *
  * @since 1.0
@@ -54,17 +52,17 @@ public class SystemMessages implements Serializable {
     protected String sessionExpiredURL = null;
     protected boolean sessionExpiredNotificationEnabled = false;
     protected String sessionExpiredCaption = "Session Expired";
-    protected String sessionExpiredMessage = "Take note of any unsaved data, and <u>click here</u> or press ESC key to continue.";
+    protected String sessionExpiredMessage = "Take note of any unsaved data, and click here or press ESC key to continue.";
 
     protected String internalErrorURL = null;
     protected boolean internalErrorNotificationEnabled = true;
     protected String internalErrorCaption = "Internal error";
-    protected String internalErrorMessage = "Please notify the administrator.<br>Take note of any unsaved data, and <u>click here</u> or press ESC to continue.";
+    protected String internalErrorMessage = "Please notify the administrator. Take note of any unsaved data, and click here or press ESC to continue.";
 
     protected String cookiesDisabledURL = null;
     protected boolean cookiesDisabledNotificationEnabled = true;
     protected String cookiesDisabledCaption = "Cookies disabled";
-    protected String cookiesDisabledMessage = "This application requires cookies to function.<br>Please enable cookies in your browser and <u>click here</u> or press ESC to try again.";
+    protected String cookiesDisabledMessage = "This application requires cookies to function. Please enable cookies in your browser and click here or press ESC to try again.";
 
     /**
      * Private constructor

flow-tests/test-root-context/src/test/java/com/vaadin/flow/uitest/ui/LogoutIT.java

@@ -34,7 +34,7 @@ public void setLocationWithNotificationDisabled_noErrorMessages() {
         // Strings defined in com.vaadin.flow.server.SystemMessages
         checkLogsForErrors(
                 msg -> msg.contains("Session Expired") || msg.contains(
-                        "Take note of any unsaved data, and <u>click here</u> or press ESC key to continue."));
+                        "Take note of any unsaved data, and click here or press ESC key to continue."));
 
         // There can't be any error dialog
         Assert.assertFalse(isElementPresent(By.className("v-system-error")));

flow-tests/test-root-context/src/test/java/com/vaadin/flow/uitest/ui/LogoutWithNotificationIT.java

@@ -39,8 +39,8 @@ public void setLocationWithNotificationEnabled_noErrorMessages() {
         // There can be "Session Expired" message because of heartbeat
         // Strings defined in com.vaadin.flow.server.SystemMessages
         checkLogsForErrors(msg -> msg.contains("Session Expired")
-                || msg.contains("Take note of any unsaved data, and <u>click "
-                        + "here</u> or press ESC key to continue."));
+                || msg.contains("Take note of any unsaved data, and click "
+                        + "here or press ESC key to continue."));
 
         // There can't be any error dialog
         Assert.assertFalse(isElementPresent(By.className("v-system-error")));