Correct use of String.toLowerCase/.toUpperCase
diff --git a/docmlet/org.eclipse.statet.docmlet.wikitext.commonmark.core/src/org/eclipse/statet/internal/docmlet/wikitext/commonmark/core/ProcessingContext.java b/docmlet/org.eclipse.statet.docmlet.wikitext.commonmark.core/src/org/eclipse/statet/internal/docmlet/wikitext/commonmark/core/ProcessingContext.java
index 6269237..ce01bb8 100644
--- a/docmlet/org.eclipse.statet.docmlet.wikitext.commonmark.core/src/org/eclipse/statet/internal/docmlet/wikitext/commonmark/core/ProcessingContext.java
+++ b/docmlet/org.eclipse.statet.docmlet.wikitext.commonmark.core/src/org/eclipse/statet/internal/docmlet/wikitext/commonmark/core/ProcessingContext.java
@@ -125,7 +125,7 @@
 	}
 	
 	public @Nullable UriWithTitle getNamedUri(final String label) {
-		return this.links.get(label.toLowerCase());
+		return this.links.get(label.toLowerCase(Locale.ROOT));
 	}
 	
 	public @Nullable String generateHeadingId(final int headingLevel, final @Nullable String headingText) {