Set default retries/version for SNMP LoginScanner

Set in snmp_login but missed in the LoginScanner.

MSP-12668

Author: wvu

lib/metasploit/framework/login_scanner/snmp.rb

@@ -12,6 +12,8 @@ class SNMP
         include Metasploit::Framework::LoginScanner::Base
 
         DEFAULT_PORT         = 161
+        DEFAULT_RETRIES      = 0
+        DEFAULT_VERSION      = 'all'
         LIKELY_PORTS         = [ 161, 162 ]
         LIKELY_SERVICE_NAMES = [ 'snmp' ]
         PRIVATE_TYPES        = [ :password ]
@@ -117,6 +119,8 @@ def has_write_access?(snmp_client, value)
         def set_sane_defaults
           self.connection_timeout = 2 if self.connection_timeout.nil?
           self.port = DEFAULT_PORT if self.port.nil?
+          self.retries = DEFAULT_RETRIES if self.retries.nil?
+          self.version = DEFAULT_VERSION if self.version.nil?
         end
 
         # This method takes an snmp client and tests whether