fix typo in migrate command

Signed-off-by: Seblu <sebastien.luttringer@smartjog.com>

cccli/command/migrate.py

@@ -2,7 +2,7 @@
 #coding=utf8
 
 '''
-CloudControl jobs command
+CloudControl migrate command
 '''
 
 from cccli.exception import *
@@ -15,7 +15,7 @@ class Command_migrate(TqlCommand):
 
     def __init__(self, cli, argv0):
         TqlCommand.__init__(self, cli, argv0)
-        self.set_usage("%prog [options] [source tql] [dest tql]")
+        self.set_usage("%prog [options] <source tql> <dest tql>")
         self.remove_option("--direct")
         self.remove_option("--raw")
         self.remove_option("--print-tql")