Revert "Fix often occurring bug when testing UI"

This reverts commit 987af951d8.

tests/ui/main.py

@@ -901,6 +901,16 @@ try:
             driver, By.XPATH, "//input[@type='file' and @name='file']"
         ).send_keys(join(Path.cwd(), "test.zip"))
 
+        access_page(
+            driver,
+            driver_wait,
+            "//div[@data-plugins-upload='']//button[@type='submit']",
+            "plugins",
+            False,
+        )
+
+        assert_alert_message(driver, "is not a valid plugin")
+
         print(
             "The bad plugin has been rejected, trying to add a good plugin ...",
             flush=True,
@@ -918,6 +928,8 @@ try:
             False,
         )
 
+        assert_alert_message(driver, "Successfully created plugin")
+
         external_plugins = safe_get_element(
             driver,
             By.XPATH,