Config: Allow ending a file with "=" and no newline

This is a perfectly valid construction according to C git:

$ echo -en '[a]\nx =' > foo.config
$ git config -f foo.config a.x; echo $?

0

Change-Id: Icfcf8304adb43c79e2b8b998f8d651b2a94f6acb

org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ConfigTest.java

@@ -726,6 +726,15 @@ public class ConfigTest {
 		assertArrayEquals(new String[]{""}, c.getStringList("a", null, "x"));
 	}
 
+	@Test
+	public void testEmptyValueAtEof() throws Exception {
+		String text = "[a]\nx =";
+		Config c = parse(text);
+		assertEquals("", c.getString("a", null, "x"));
+		c = parse(text + "\n");
+		assertEquals("", c.getString("a", null, "x"));
+	}
+
 	private static void assertReadLong(long exp) throws ConfigInvalidException {
 		assertReadLong(exp, String.valueOf(exp));
 	}

org.eclipse.jgit/src/org/eclipse/jgit/lib/Config.java

@@ -1200,8 +1200,6 @@ public class Config {
 		for (;;) {
 			int c = in.read();
 			if (c < 0) {
-				if (value.length() == 0)
-					throw new ConfigInvalidException(JGitText.get().unexpectedEndOfConfigFile);
 				break;
 			}