fixed nil issue

Author: darkoperator

modules/exploits/windows/local/persistence.rb

@@ -163,7 +163,7 @@ def log_file(log_path = nil)
 	#-------------------------------------------------------------------------------
 	def write_script_to_target(vbs,name)
 		tempdir = session.fs.file.expand_path("%TEMP%")
-		if name
+		if name == nil
 			tempvbs = tempdir + "\\" + Rex::Text.rand_text_alpha((rand(8)+6)) + ".vbs"
 		else
 			tempvbs = tempdir + "\\" + name + ".vbs"