SystemReader: Use correct constructor of FileBasedConfig

The merge done in change If0c5010a2 resolved a conflict incorrectly
and reverted the fix that was done in change Id0bcdc93b.

Change-Id: I0f5fde33d1f366817f2b966eb42535f7bd3b063e
Reported-by: Thomas Wolf <thomas.wolf@paranor.ch>
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit/src/org/eclipse/jgit/util/SystemReader.java

@@ -126,7 +126,7 @@ public abstract class SystemReader {
 					return new FileBasedConfig(parent, configFile, fs);
 				}
 			}
-			return new FileBasedConfig(null, fs) {
+			return new FileBasedConfig(parent, null, fs) {
 				@Override
 				public void load() {
 					// empty, do not load