Only install sysinstall.8 if the release/sysinstall directory exists.  This fixes the world for people without src-release.
Only install sysinstall.8 if the release/sysinstall directory exists.  This
fixes the world for people without src-release.

PR:		24122
Submitted by:	Steven G. Kargl <kargl@apl.washington.edu>

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase