fix: remove unbalanced saveGraphicsState

Each time saveGraphicsState must be called in pair with
restoreGraphicsState. Otherwise it could cause unexpected behaviour
(crash during call on macOS 10.14)

Change-Id: If7a10671c84bb4dd4fd67541fcaa3237ee66abe4
Reviewed-by: Andreas Traczyk <andreas.traczyk@savoirfairelinux.com>

src/views/IconButton.mm

@@ -175,7 +175,6 @@
             [bottomRightPath appendBezierPathWithPoints:pointArrayBottom count:3];
             [bottomRightPath appendBezierPathWithArcFromPoint: bottomLeft toPoint: bottom radius: 20.0f];
             [bottomRightPath fill];
-            [NSGraphicsContext saveGraphicsState];
             return;
         }