Fix an error occurs when replacing project.
Fix an error occurs when replacing project.

Add a ContainsKey if statement to avoid ArgumentException when parsing dictionary for existing project file.

Signed-off-by: onevcat <58d0c0df3ea9eba666b421252347024513bf8bb5@gmail.com>

onevcat/XUPorter,maoi/XUPorter,sq5gvm/XUPorter,zhutaorun/XUPorter,trampliu/XUPorter,karlgluck/XUPorter,foolhuang/XUPorter