core:WarnShortSSOInterval: Fix spelling error.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@2329 44740490-163a-0410-bde0-09ae8108e29a

modules/core/dictionaries/short_sso_interval.definition.json

@@ -3,7 +3,7 @@
 		"en": "We have detected that there is only a few seconds since you last authenticated with this service provider, and therefore assume that there is a problem with this SP."
 	},
 	"warning_header": {
-		"en": "To short interval between single sign on events."
+		"en": "Too short interval between single sign on events."
 	},
 	"retry": {
 		"en": "Retry login"