Use try-with-resources in FileContentManager

Manually adjusted the JDT cleanup as the try in a try block looked
unnecessary.

Change-Id: If193933cf8396993ab29c6ba87b268b8587e2300
Signed-off-by: Lars Vogel <Lars.Vogel@vogella.com>
diff --git a/bundles/org.eclipse.team.core/src/org/eclipse/team/internal/core/FileContentManager.java b/bundles/org.eclipse.team.core/src/org/eclipse/team/internal/core/FileContentManager.java
index 6063fd5..3faff38 100644
--- a/bundles/org.eclipse.team.core/src/org/eclipse/team/internal/core/FileContentManager.java
+++ b/bundles/org.eclipse.team.core/src/org/eclipse/team/internal/core/FileContentManager.java
@@ -96,18 +96,15 @@
 			if (!f.exists())
 				return false;
 
-			try {
-				DataInputStream input = new DataInputStream(new FileInputStream(f));
-				try {
+			try (DataInputStream input = new DataInputStream(new FileInputStream(f))) {
 					map.putAll(readOldFormatExtensionMappings(input));
-				} finally {
-					input.close();
-					f.delete();
-				}
 			} catch (IOException ex) {
 				TeamPlugin.log(IStatus.ERROR, ex.getMessage(), ex);
 				return false;
+			} finally {
+				f.delete();
 			}
+
 			return true;
 		}