[build] Only sign builds if they are tagged.

Author: Breakthrough

appveyor.yml

@@ -26,7 +26,9 @@ deploy:
 - provider: Webhook
   url: https://app.signpath.io/API/v1/f2efa44c-5b5c-45f2-b44f-8f9dde708313/Integrations/AppVeyor?ProjectSlug=DVR-Scan&SigningPolicySlug=release-signing
   authorization:
-     secure: FBgWCaxCCKOqc2spYf5NGWSNUGLbT5WeuC5U0k4Of1Ids9n51YWxhGlMyzLbdNBFe64RUcOSzk/N3emlQzbsJg==
+    secure: FBgWCaxCCKOqc2spYf5NGWSNUGLbT5WeuC5U0k4Of1Ids9n51YWxhGlMyzLbdNBFe64RUcOSzk/N3emlQzbsJg==
+  on:
+    APPVEYOR_REPO_TAG: true # keep casing this way for Linux builds where variables are case-sensitive
 
 install:
   - echo * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *