pgm: Handle exceptions in LsTree command

This avoids we show a stacktrace on the console by default when this
type of exception is thrown during the run method is executed.

Change-Id: Ib3ae59eeb90143eca1a0b515c59457a0eb2cc383
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/LsTree.java

@@ -45,6 +45,7 @@
 
 package org.eclipse.jgit.pgm;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -72,7 +73,7 @@ class LsTree extends TextBuiltin {
 
 	/** {@inheritDoc} */
 	@Override
-	protected void run() throws Exception {
+	protected void run() {
 		try (TreeWalk walk = new TreeWalk(db)) {
 			walk.reset(); // drop the first empty tree, which we do not need here
 			if (paths.size() > 0)
@@ -95,6 +96,8 @@ class LsTree extends TextBuiltin {
 				outw.print(QuotedString.GIT_PATH.quote(walk.getPathString()));
 				outw.println();
 			}
+		} catch (IOException e) {
+			throw die(e.getMessage(), e);
 		}
 	}
 }