Update Email.rst

Author: ThomasLandauer

reference/constraints/Email.rst

@@ -140,7 +140,7 @@ address. Valid values are:
   as the `HTML5 email input element`_, making the backend validation consistent
   with the one provided by browsers;
 * ``strict`` uses the `egulias/email-validator`_ library (which you must
-  install separately) to validate according to `RFC 5322`_.
+  install separately) for validation according to `RFC 5322`_.
 
 The default value used by this option is set in the
 :ref:`framework.validation.email_validation_mode <reference-validation-email_validation_mode>`