HPCC-9403 fix non-default user home directory related issues

Previously "home" variable in environment.conf is set to system default
user directory base (useradd -D), i.e. /home on most Linux. In order
to fix it for non-default user directory, in source file
initfiles/bash/etc/init.d/install-init.in user home directory is retrieved
from /etc/passwd after user created/detected and assigned to "home" variable
in environment.conf