convert to UTF-8

Signed-off-by: Florian Thienel <florian@thienel.org>
diff --git a/org.eclipse.vex.docbook/styles/docbook-plain.css b/org.eclipse.vex.docbook/styles/docbook-plain.css
index 5c52cd7..f3dfdc6 100644
--- a/org.eclipse.vex.docbook/styles/docbook-plain.css
+++ b/org.eclipse.vex.docbook/styles/docbook-plain.css
@@ -987,15 +987,15 @@
 }
 productname[class="registered"]:after {
 	display: inline;
-	content: '®';
+	content: '®';
 }
 productname[class="trade"]:after {
 	display: inline;
-	content: '™';
+	content: '™';
 }
 productname[class="copyright"]:before {
 	display: inline;
-	content: '©';
+	content: '©';
 }
 
 productnumber {