replace csh to sh in src/etc/Makefile

[Matthew Dillon]

:> this fix won't work as sh won't expand the [] right. besides you ought 
:> to have /bin/csh, this is the traditional shell of BSD if i'm informed 
:> right
:> 
:> cheers
:>   simon
:
:yes now i see that's, so sorry for dumb patch
:-- 
:        - regards bj

    Yah, I think we won't support NO_TCSH.  The system has to have a 
    /bin/csh.  Someone in FreeBSD land added that option before we forked
    but the commit logs have no explanation as to why such an option would
    be useful.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>