Backport 2.7: Use "#!/usr/bin/env perl" as shebang line.
diff --git a/tests/scripts/gen_gcm_encrypt.pl b/tests/scripts/gen_gcm_encrypt.pl
index 8adbbce..29ec677 100755
--- a/tests/scripts/gen_gcm_encrypt.pl
+++ b/tests/scripts/gen_gcm_encrypt.pl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
 #
 # Based on NIST gcmEncryptIntIVxxx.rsp validation files
 # Only first 3 of every set used for compile time saving