Fix the problem for the GitHubIssuePanel #26

- Hide Assign yourself link button when a repository is not mine

Author: junichi11

src/main/java/com/junichi11/netbeans/modules/github/issues/issue/ui/GitHubIssuePanel.form

@@ -275,7 +275,7 @@
                               </Group>
                               <EmptySpace min="-2" pref="37" max="-2" attributes="0"/>
                               <Group type="103" groupAlignment="0" attributes="0">
-                                  <Component id="descriptionTabbedPanel" pref="412" max="32767" attributes="0"/>
+                                  <Component id="descriptionTabbedPanel" max="32767" attributes="0"/>
                                   <Component id="titleTextField" max="32767" attributes="0"/>
                               </Group>
                               <EmptySpace max="-2" attributes="0"/>

src/main/java/com/junichi11/netbeans/modules/github/issues/issue/ui/GitHubIssuePanel.java

@@ -360,6 +360,7 @@ private void setCollaboratorsComponentsVisible(boolean isVisible) {
         milestoneComboBox.setVisible(isVisible);
         assigneeLabel.setVisible(isVisible);
         assigneeComboBox.setVisible(isVisible);
+        assignYourselfLinkButton.setVisible(isVisible);
         newLabelButton.setVisible(isVisible);
         newMilestoneButton.setVisible(isVisible);
     }