s4-param Don't set variables such as the debuglevel unless global

s4-param Don't set variables such as the debuglevel unless global

This ensures that when a second lp_ctx is created, that it does not
set global variables such as the debug level, log file etc,
potentially overriding the settings created by another context.

In particular this matters when loading Samba4 modules into Samba3.

Andrew Bartlett