Don't hard-code section names, use ConfigConstants instead

Change-Id: Ie2dde43da491fa27b25a2ad8014866d77d484b24
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/src/org/eclipse/jgit/api/PullCommand.java

@@ -194,7 +194,8 @@ public class PullCommand extends GitCommand<PullResult> {
 		String remoteUri;
 		FetchResult fetchRes;
 		if (isRemote) {
-			remoteUri = repoConfig.getString("remote", remote,
+			remoteUri = repoConfig.getString(
+					ConfigConstants.CONFIG_REMOTE_SECTION, remote,
 					ConfigConstants.CONFIG_KEY_URL);
 			if (remoteUri == null) {
 				String missingKey = ConfigConstants.CONFIG_REMOTE_SECTION + DOT