tdf#123050: catch object does not have a key labeled 'theme_data'

json::document_error: node::child: this object does not have a key labeled 'theme_data'

Change-Id: Ic4daf53cff4e3e25b83393cb92957bf60cd5a92c
Reviewed-on: https://gerrit.libreoffice.org/67161
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

cui/source/options/personalization.cxx

@@ -815,10 +815,10 @@ PersonaInfo parseSingleResponse(const std::string& rResponse)
         return PersonaInfo();
     }
 
-    auto theme_data = aDocumentRoot.child("theme_data");
-
     try
     {
+        auto theme_data = aDocumentRoot.child("theme_data");
+
         PersonaInfo aNewPersona = {
             OUString(),
             OStringToOUString( OString(theme_data.child("name").string_value().get()),