doc: remove extra 'in's

'when in an' -> 'when an'

PR-URL: nodejs/node#43705
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

doc/api/process.md

@@ -340,7 +340,7 @@ changes:
 * `err` {Error} The uncaught exception.
 * `origin` {string} Indicates if the exception originates from an unhandled
   rejection or from a synchronous error. Can either be `'uncaughtException'` or
-  `'unhandledRejection'`. The latter is used when in an exception happens in a
+  `'unhandledRejection'`. The latter is used when an exception happens in a
   `Promise` based async context (or if a `Promise` is rejected) and
   [`--unhandled-rejections`][] flag set to `strict` or `throw` (which is the
   default) and the rejection is not handled, or when a rejection happens during
@@ -438,7 +438,7 @@ added:
 * `err` {Error} The uncaught exception.
 * `origin` {string} Indicates if the exception originates from an unhandled
   rejection or from synchronous errors. Can either be `'uncaughtException'` or
-  `'unhandledRejection'`. The latter is used when in an exception happens in a
+  `'unhandledRejection'`. The latter is used when an exception happens in a
   `Promise` based async context (or if a `Promise` is rejected) and
   [`--unhandled-rejections`][] flag set to `strict` or `throw` (which is the
   default) and the rejection is not handled, or when a rejection happens during