Log message:
Pullup ticket #5631 - requested by sevan
sysutils/beats: build fix

Revisions pulled up:
- sysutils/beats/Makefile                                       1.19

---
   Module Name:    pkgsrc
   Committed By:   fhajny
   Date:           Thu Nov  2 15:30:50 UTC 2017

   Modified Files:
           pkgsrc/sysutils/beats: Makefile

   Log message:
   sysutils/beats: Provide a better hint to where libpcap is. May fix
   the build in some situations.