fix: integ test after problems panel performance improvement

Author: abose

test/spec/PreferencesManager-integ-test.js

@@ -107,7 +107,7 @@ define(function (require, exports, module) {
 
             await awaitsForDone(SpecRunnerUtils.openProjectFiles("test.json"));
             await awaitsFor(()=>{
-                return !testWindow.$("#problems-panel").text().includes(Strings.ERROR_PREFS_PROJECT_LINT_MESSAGE);
+                return !testWindow.$("#problems-panel").is(":visible");
             }, "problem panel should not be there for normal test.json file");
 
             await awaitsForDone(SpecRunnerUtils.openProjectFiles(".brackets.json"));