Fix literal \n in jobs -i

Regression from rapid7#4063.

Author: wvu

lib/msf/ui/console/command_dispatcher/jobs.rb

@@ -165,7 +165,7 @@ def cmd_jobs(*args)
                 job = framework.jobs[job_id.to_s]
                 mod = job.ctx[0]
 
-                output  = '\n'
+                output  = "\n"
                 output += "Name: #{mod.name}"
                 output += ", started at #{job.start_time}" if job.start_time
                 print_line(output)