removing of unused imports together with some general code refactoring

plugins/dbms/firebird/__init__.py

@@ -10,7 +10,6 @@ See the file 'doc/COPYING' for copying permission
 from lib.core.enums import DBMS
 from lib.core.settings import FIREBIRD_SYSTEM_DBS
 from lib.core.unescaper import unescaper
-
 from plugins.dbms.firebird.enumeration import Enumeration
 from plugins.dbms.firebird.filesystem import Filesystem
 from plugins.dbms.firebird.fingerprint import Fingerprint

plugins/dbms/firebird/connector.py

@@ -15,7 +15,6 @@ except ImportError, _:
 from lib.core.data import logger
 from lib.core.exception import sqlmapConnectionException
 from lib.core.settings import UNICODE_ENCODING
-
 from plugins.generic.connector import Connector as GenericConnector
 
 class Connector(GenericConnector):

plugins/dbms/firebird/filesystem.py

@@ -8,7 +8,6 @@ See the file 'doc/COPYING' for copying permission
 """
 
 from lib.core.exception import sqlmapUnsupportedFeatureException
-
 from plugins.generic.filesystem import Filesystem as GenericFilesystem
 
 class Filesystem(GenericFilesystem):

plugins/dbms/firebird/fingerprint.py

@@ -9,7 +9,6 @@ See the file 'doc/COPYING' for copying permission
 
 import re
 
-from lib.core.agent import agent
 from lib.core.common import Backend
 from lib.core.common import Format
 from lib.core.common import getUnicode
@@ -24,8 +23,6 @@ from lib.core.settings import FIREBIRD_ALIASES
 from lib.core.settings import METADB_SUFFIX
 from lib.core.settings import UNKNOWN_DBMS_VERSION
 from lib.request import inject
-from lib.request.connect import Connect as Request
-
 from plugins.generic.fingerprint import Fingerprint as GenericFingerprint
 
 class Fingerprint(GenericFingerprint):

plugins/dbms/firebird/takeover.py

@@ -8,7 +8,6 @@ See the file 'doc/COPYING' for copying permission
 """
 
 from lib.core.exception import sqlmapUnsupportedFeatureException
-
 from plugins.generic.takeover import Takeover as GenericTakeover
 
 class Takeover(GenericTakeover):