Remove duplicate word

Author: nicwortel

frontend/asset_mapper.rst

@@ -1069,7 +1069,7 @@ scripting attacks, the inline ``<script>`` tags rendered by the ``importmap()``
 function will likely violate that policy and will not be executed by the browser.
 
 To allow these scripts to run without disabling the security provided by
-the CSP, you can can generate a secure random string for every request (called
+the CSP, you can generate a secure random string for every request (called
 a *nonce*) and include it in the CSP header and in a ``nonce`` attribute on
 the ``<script>`` tags.
 The ``importmap()`` function accepts an optional second argument that can be