Skip --from files when finding the commit

Author: yosifkit

generate-stackbrew-library.sh

@@ -37,6 +37,9 @@ dirCommit() {
 			$(git show HEAD:./Dockerfile | awk '
 				toupper($1) == "COPY" {
 					for (i = 2; i < NF; i++) {
+						if ($i ~ /^--from=/) {
+							next
+						}
 						print $i
 					}
 				}