run.sh: Add set -e to halt on any unexpected errors

Author: arrowmaster

assets/nix/run.sh

@@ -60,6 +60,7 @@ corlib_dir=""
 
 ################################################################################
 # Everything past this point is the actual script
+set -e
 
 # Special case: program is launched via Steam
 # In that case rerun the script via their bootstrapper to ensure Steam overlay works