Fix build bustage due to change in header file from Boolean to PRBool

on XFE_Image::isImageLoaded().

cmd/xfe/src/Image.cpp

@@ -187,7 +187,7 @@ XFE_Image::~XFE_Image(void)
 
 
 /* returns if the image has been completely loaded */
-Boolean 
+PRBool
 XFE_Image::isImageLoaded(void)
 {
      return (completelyLoaded);