Fix white space condensing not functioning when reading a scenario

Since dialogs turn off whitespace condensing, and it's a global flag,
that caused scenarios to be read with the flag disabled.
The solution is for scenarios to directly turn the flag on before reading.

src/fileio/fileio_scen.cpp

@@ -698,6 +698,7 @@ void readScenarioFromXml(ticpp::Document&& data, cScenario& scenario) {
 		"language", "author", "text", "ratings",
 		"flags", "creator", "game", "editor"
 	};
+	TiXmlBase::SetCondenseWhiteSpace(true);
 	for(elem = elem.begin(data.FirstChildElement()); elem != elem.end(); elem++) {
 		elem->GetValue(&type);
 		reqs.erase(type);