Update 1.1.2.md

Author: punker76

docs/release-notes/1.1.2.md

@@ -10,3 +10,4 @@ This is a bug fix release of MahApps.Metro.
 - Fixed upgrading the `WindowPlacementSettings` on version change #1787 #1736 (ada352b)
 - Fixed a painting issue of the entire window and the maximize action (5ae97f9)
 - Fixed another `Topmost` bug: Window is going behind other windows on program start #1251 (6b0a8fa)
+- Fixed brief flashing window when launched (e.g. from the explorer) #1781 (4b42fe0)