Fix some non-nls warnings.

Change-Id: Ib3570b7301e8385d5f0c866664aa317b4221bda0
Signed-off-by: Alexander Kurtakov <akurtako@redhat.com>
diff --git a/bundles/org.eclipse.releng.tools/src/org/eclipse/releng/tools/XmlFile.java b/bundles/org.eclipse.releng.tools/src/org/eclipse/releng/tools/XmlFile.java
index 924cf27..a03ef33 100644
--- a/bundles/org.eclipse.releng.tools/src/org/eclipse/releng/tools/XmlFile.java
+++ b/bundles/org.eclipse.releng.tools/src/org/eclipse/releng/tools/XmlFile.java
@@ -127,7 +127,7 @@
 		String tidyComment = comment.trim();
 
 		//Append new-line at the end for cleaner look.
-		tidyComment += "\n";
+		tidyComment += '\n';
 
 		// check for existance of an xml header (<?xml)
 		// If so, put the comment 'below' it.
@@ -137,7 +137,7 @@
 		//    comment start....
 		if (containsXmlEncoding(document)) {
 			// If encoding is present, pre-append a new line.
-			tidyComment = "\n" + tidyComment; //$NON-NLS-1$
+			tidyComment = '\n' + tidyComment;
 		}
 
 		//------------------ COMMENT INSERT