Fix typo in github token env variable

Author: imlucas

.evergreen.yml

@@ -289,7 +289,7 @@ functions:
         export PATH="${node_path}:$PATH"
         export CI=1
         export EVERGREEN=1
-        export GTIHUB_TOKEN=${leafybot_github_token}
+        export GITHUB_TOKEN=${leafybot_github_token}
         test -n '${add_env_appdata|}' && export APPDATA='${add_env_appdata|}'
         ${npm|npm} run upload;