Fix typo (#11186)

Change-Id: I3b1077f5962a196285b01f4784fe10914607e07b
Merge commit '65052825df68c109d290bb12ca28b18a2ea613fe' into master

6505282 Fix typo (#11186)

Conflicts:
	server/src/com/vaadin/annotations/Widgetset.java

Change-Id: Ibc49522651b1063baefc0010f7429f2b95a261ab