Minor bug fixes to --os-shell (altought web backdoor functionality still to be reviewed).

Minor common library code refactoring.
Code cleanup.
Set back the default User-Agent to sqlmap for comparison algorithm reasons.
Updated THANKS.

lib/controller/checks.py

@@ -27,7 +27,6 @@ Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 import re
 import time
 
-from lib.controller.action import action
 from lib.core.agent import agent
 from lib.core.common import randomInt
 from lib.core.common import randomStr
@@ -295,9 +294,9 @@ def checkStability():
     infoMsg = "testing if the url is stable, wait a few seconds"
     logger.info(infoMsg)
 
-    firstPage, firstHeaders = Request.queryPage(content=True)
+    firstPage, _ = Request.queryPage(content=True)
     time.sleep(1)
-    secondPage, secondHeaders = Request.queryPage(content=True)
+    secondPage, _ = Request.queryPage(content=True)
 
     condition = firstPage == secondPage
 

lib/controller/controller.py

@@ -36,7 +36,6 @@ from lib.core.common import readInput
 from lib.core.data import conf
 from lib.core.data import kb
 from lib.core.data import logger
-from lib.core.exception import sqlmapConnectionException
 from lib.core.exception import sqlmapNotVulnerableException
 from lib.core.session import setInjection
 from lib.core.target import createTargetDirs
@@ -105,7 +104,6 @@ def start():
         logger.info(infoMsg)
 
     hostCount               = 0
-    receivedCookies         = []
     cookieStr               = ""
     setCookieAsInjectable   = True