gui: fix condition handling for lists

Base class must be called first, otherwise the condition can never
again become true. Fixes font size switching in Material theme.

Change-Id: I160a733549495e1bde3cead56b0a3582f0dc744c
diff --git a/gui/fileselector.cpp b/gui/fileselector.cpp
index 4a26349..319b11b 100644
--- a/gui/fileselector.cpp
+++ b/gui/fileselector.cpp
@@ -171,11 +171,11 @@
 
 int GUIFileSelector::NotifyVarChange(const std::string& varName, const std::string& value)
 {
+	GUIScrollList::NotifyVarChange(varName, value);
+
 	if(!isConditionTrue())
 		return 0;
 
-	GUIScrollList::NotifyVarChange(varName, value);
-
 	if (varName.empty()) {
 		// Always clear the data variable so we know to use it
 		DataManager::SetValue(mVariable, "");