Fix setting email for service user

Setting an email address for a service user failed with
a NullPointerException, leading to a 500 response when trying to set the
email via RestAPI or UI.

Change-Id: Ide6d18250385ded1908c584f713fa2d0715833b6
diff --git a/src/main/java/com/googlesource/gerrit/plugins/serviceuser/PutEmail.java b/src/main/java/com/googlesource/gerrit/plugins/serviceuser/PutEmail.java
index 135e34f..4a5c6f6 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/serviceuser/PutEmail.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/serviceuser/PutEmail.java
@@ -95,7 +95,7 @@
       EmailInput in = new EmailInput();
       in.email = input.email;
       in.noConfirmation = true;
-      createEmail.get().apply(rsrc.getUser(), IdString.fromDecoded(email), in);
+      createEmail.get().apply(rsrc.getUser(), IdString.fromDecoded(in.email), in);
       putPreferred.get().apply(rsrc.getUser(), input.email);
       return Response.ok(input.email);
     }