Remove notification settings from appveyor.yml

Notifications can be (and should be) configured on account basis on
the CI web site.  This avoids getting emails to openssl-commits for
personal accounts that also build OpenSSL stuff.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3484)
(cherry picked from commit 7a94f5b0f7c878b1056a08f659ce23aa97bfa3ad)

appveyor.yml

@@ -50,11 +50,3 @@ build_script:
 
 test_script:
     - nmake /f ms\%MAK% test
-
-notifications:
-    - provider: Email
-      to:
-          - openssl-commits@openssl.org
-      on_build_success: false
-      on_build_failure: true
-      on_build_status_changed: true