phantom TitleBar rect glitch when conditionnal call to BeginNodeTitleBar

[vlmillet]

If, from one frame to another, we call or don't call BeginNodeTitleBar on a specific node (depending on a condition for my case), a glitching rect stays on the screen.
It is due to a missing value reset of title bar content rect in BeginNode().

Adding node.TitleBarContentRect = ImRect(); in BeginNode() solves the issue