Fix warning: ‘-textValue’ not found in protocol(s)

Confusingly, labelNode is a DOMElement, not a DOMNode, so textValue cannot
apply here; textContent which would be an appropriate replacement does not
exist AFAIK in this DOM Library.

So we manually get the text node via firstChild then get its text value
via nodeValue.

SoObjects/Mailer/SOGoMailAccounts.m

@@ -234,7 +234,7 @@
           labelNode = [labelNodes objectAtIndex: count];
           
           label = [labelNode attribute: @"id"];
-          name = [labelNode textValue];
+          name = [[labelNode firstChild] nodeValue];
           color = [labelNode attribute: @"color"];
 
           [values addObject: name];