Change default sensu_yum_repo_url to use HTTPS

Switch sensu_yum_repo_url to use HTTPS by default

defaults/main.yml

@@ -12,7 +12,7 @@ sensu_enterprise_package: sensu-enterprise
 sensu_enterprise_dashboard_package: sensu-enterprise-dashboard
 
 # Sensu repo urls
-sensu_yum_repo_url: "http://repositories.sensuapp.org/yum/$releasever/$basearch/"
+sensu_yum_repo_url: "https://repositories.sensuapp.org/yum/$releasever/$basearch/"
 sensu_apt_repo_url: "deb     http://repositories.sensuapp.org/apt {{ ansible_distribution_release }} main"
 sensu_apt_key_url: "http://repositories.sensuapp.org/apt/pubkey.gpg"
 sensu_freebsd_url: "https://sensu.global.ssl.fastly.net/freebsd/FreeBSD:{{ ansible_distribution_major_version }}:{{ ansible_architecture }}/"