Fix errors in configuration

[vankoven]

Change log:

• fix issue Crash on creating multiple server groups #698 .
• display configuration parsing errors without rate limit.
• fix issue cfg: wrong position is printed in log messages in case of parser error #65 , display error in the correct way, e.g print message:

[18638.202740] [tempesta] ERROR: invalid number of values; expected: 1, got: 0
[18638.204503] [tempesta] ERROR: Unable to parse 'listen' value: 'No value specified'
[18638.206276] [tempesta] ERROR: configuration parsing error:
                  5: listen; # 80;
                     ^^^^^^^^^^^^^
[18638.208295] [tempesta] ERROR: failed to start modules

for configuration:

cache 0;
listen 80;
server 127.0.0.1:8080;
# some comment here
listen; # 80;
# some comment here
# some comment here
# some comment here
# some comment here
# some comment here

[krizhanovsky]

Just a few minor notes from my side, I didn't look too deeper to the changes. Review approval from @keshonok is required.

[krizhanovsky]

Please don't forget to update copyright year in modified files

[krizhanovsky]

"NL" isn't obvious suffix, please leave a comment like /* Not-limited printing for .... */