Diff viewer preference page has wrong button sizes in Mars (bug 471161)

https://bugs.eclipse.org/bugs/show_bug.cgi?id=471161

git-svn-id: https://dev.eclipse.org/svnroot/technology/org.eclipse.subversive/trunk@21484 ee007c2a-0a25-0410-9ab9-bf268980928c

org.eclipse.team.svn.ui/src/org/eclipse/team/svn/ui/composite/DiffViewerFileAssociationsComposite.java

@@ -240,6 +240,7 @@ public class DiffViewerFileAssociationsComposite extends Composite {
 		
 		GridData data = new GridData();
 		data.verticalAlignment = SWT.TOP;
+		data.widthHint = 100;
 		composite.setLayout(layout);
 		composite.setLayoutData(data);