DownloadTest: Use enums from org.apache.http.HttpStatus

Instead of using hard-coded HTTP status codes, use the enums
which makes it a bit easier to see what's expected.

Change-Id: I2da5d25632f374b8625d64da4df70d1c9c406bb1
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit.lfs.server.test/tst/org/eclipse/jgit/lfs/server/fs/DownloadTest.java

@@ -42,6 +42,8 @@
  */
 package org.eclipse.jgit.lfs.server.fs;
 
+import static org.apache.http.HttpStatus.SC_NOT_FOUND;
+import static org.apache.http.HttpStatus.SC_UNPROCESSABLE_ENTITY;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.fail;
 
@@ -80,7 +82,8 @@ public class DownloadTest extends LfsServerTest {
 		} catch (RuntimeException e) {
 			String error = String.format(
 					"Invalid pathInfo '/%s' does not match '/{SHA-256}'", id);
-			assertEquals(formatErrorMessage(422, error), e.getMessage());
+			assertEquals(formatErrorMessage(SC_UNPROCESSABLE_ENTITY, error),
+					e.getMessage());
 		}
 	}
 
@@ -95,7 +98,8 @@ public class DownloadTest extends LfsServerTest {
 			fail("expected RuntimeException");
 		} catch (RuntimeException e) {
 			String error = String.format("Invalid id: : %s", id);
-			assertEquals(formatErrorMessage(422, error), e.getMessage());
+			assertEquals(formatErrorMessage(SC_UNPROCESSABLE_ENTITY, error),
+					e.getMessage());
 		}
 	}
 
@@ -110,7 +114,8 @@ public class DownloadTest extends LfsServerTest {
 			fail("expected RuntimeException");
 		} catch (RuntimeException e) {
 			String error = String.format("Object '%s' not found", id.getName());
-			assertEquals(formatErrorMessage(404, error), e.getMessage());
+			assertEquals(formatErrorMessage(SC_NOT_FOUND, error),
+					e.getMessage());
 		}
 	}