Qt: Don't rebuild library view if style hasn't changed

CHANGES

@@ -1,6 +1,8 @@
 0.6.1: (Future)
 Bugfixes:
  - Python: Fix importing .gb or .gba before .core
+Misc:
+ - Qt: Don't rebuild library view if style hasn't changed
 
 0.6.0: (2017-07-16)
 Features:

src/platform/qt/library/LibraryController.cpp

@@ -83,6 +83,9 @@ LibraryController::~LibraryController() {
 }
 
 void LibraryController::setViewStyle(LibraryStyle newStyle) {
+	if (m_currentStyle == newStyle) {
+		return;
+	}
 	m_currentStyle = newStyle;
 
 	AbstractGameList* newCurrentList = nullptr;