Fix error message for invalid username input: https://bugzilla.redhat…

….com/show_bug.cgi?id=977595

zanata-war/src/main/resources/ValidationMessages.properties

@@ -6,7 +6,7 @@ javax.validation.constraints.Max.message=must be less than or equal to {value}
 javax.validation.constraints.Min.message=must be greater than or equal to {value}
 javax.validation.constraints.NotNull.message=may not be null
 javax.validation.constraints.Past.message=must be a past date
-javax.validation.constraints.Pattern.message=must match "{regex}"
+javax.validation.constraints.Pattern.message=must match {regexp}
 javax.validation.constraints.Range.message=must be between {min} and {max}
 javax.validation.constraints.Size.message=size must be between {min} and {max}
 javax.validation.constraints.Email.message=must be a well-formed email address