Update SparkSubmissionContentPanel.java

Add login Azure steps detail  (View -> Tool Windows -> Azure Explorer)

Author: wezhang

PluginsAndFeatures/azure-toolkit-for-intellij/src/com/microsoft/azure/hdinsight/spark/ui/SparkSubmissionContentPanel.java

@@ -272,7 +272,7 @@ public void propertyChange(PropertyChangeEvent evt) {
 
         errorMessageLabels[ErrorMessageLabelTag.ClusterName.ordinal()] = new JLabel( isSignedIn ?
                         "Cluster Name Should not be null, please choose one for submission" :
-                        "Can't list cluster, please login within Azure Explorer and refresh");
+                        "Can't list cluster, please login within Azure Explorer (View -> Tool Windows -> Azure Explorer) and refresh");
         errorMessageLabels[ErrorMessageLabelTag.ClusterName.ordinal()].setForeground(DarkThemeManager.getInstance().getErrorMessageColor());
 
         clustersListComboBox.getComboBox().addItemListener(new ItemListener() {