Prefer static inner classes

Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

org.eclipse.jgit.ui/src/org/eclipse/jgit/awtui/CommitGraphPane.java

@@ -176,7 +176,7 @@ public class CommitGraphPane extends JTable {
 		}
 	}
 
-	class NameCellRender extends DefaultTableCellRenderer {
+	static class NameCellRender extends DefaultTableCellRenderer {
 		private static final long serialVersionUID = 1L;
 
 		public Component getTableCellRendererComponent(final JTable table,
@@ -194,7 +194,7 @@ public class CommitGraphPane extends JTable {
 		}
 	}
 
-	class DateCellRender extends DefaultTableCellRenderer {
+	static class DateCellRender extends DefaultTableCellRenderer {
 		private static final long serialVersionUID = 1L;
 
 		private final DateFormat fmt = new SimpleDateFormat(
@@ -215,7 +215,7 @@ public class CommitGraphPane extends JTable {
 		}
 	}
 
-	class GraphCellRender extends DefaultTableCellRenderer {
+	static class GraphCellRender extends DefaultTableCellRenderer {
 		private static final long serialVersionUID = 1L;
 
 		private final AWTPlotRenderer renderer = new AWTPlotRenderer(this);