Fix unused exception error-prone warning

Ignoring the exception seems intended in this case.

Change-Id: I9dedf61b9cb5a6ff39fb141dd5da19143f4f6978
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/LooseObjects.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/LooseObjects.java
index b9af83d..326c5f6 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/LooseObjects.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/LooseObjects.java
@@ -254,7 +254,7 @@
 					// refresh directory to work around NFS caching issue
 				}
 				return getSizeWithoutRefresh(curs, id);
-			} catch (FileNotFoundException e) {
+			} catch (FileNotFoundException unused) {
 				if (fileFor(id).exists()) {
 					throw noFile;
 				}