Remove PROTECT_VECTORS option since either program is correct without locking or it is not, especially since std::vector is definitely not thread-safe on all major platforms.

rtgui/filebrowserentry.cc

@@ -236,10 +236,7 @@ void FileBrowserEntry::updateImage (rtengine::IImage8* img, double scale, rtengi
 
 void FileBrowserEntry::_updateImage (rtengine::IImage8* img, double s, rtengine::procparams::CropParams cropParams)
 {
-
-#if PROTECT_VECTORS
     MYWRITERLOCK(l, lockRW);
-#endif
 
     redrawRequests--;
     scale = s;