Switched to Perl local::lib for local compilation.

Taken from upstream Slic3r, thanks @alexrj.

utils/send-gcode.pl

@@ -6,6 +6,7 @@ use warnings;
 BEGIN {
     use FindBin;
     use lib "$FindBin::Bin/../lib";
+    use local::lib "$FindBin::Bin/../local-lib";
 }
 
 use Slic3r;