Style: Tweaked default WindowRounding value from 9 to 7 (#707)

imgui.cpp

@@ -707,7 +707,7 @@ ImGuiStyle::ImGuiStyle()
 {
     Alpha                   = 1.0f;             // Global alpha applies to everything in ImGui
     WindowPadding           = ImVec2(8,8);      // Padding within a window
-    WindowRounding          = 9.0f;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    WindowRounding          = 7.0f;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
     WindowBorderSize        = 0.0f;             // Thickness of border around windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowTitleAlign        = ImVec2(0.0f,0.5f);// Alignment for title bar text