Fixed typo how to create an example gpg key

Reviewed-By: Nathaniel McCallum <npmccallum@redhat.com>

ipaserver/install/ipa_backup.py

@@ -42,7 +42,7 @@ from ipalib.constants import CACERT
 from ConfigParser import SafeConfigParser
 
 """
-A test gpg can be generated list this:
+A test gpg can be generated like this:
 
 # cat >keygen <<EOF
      %echo Generating a standard key