net-mgmt/blackbox_exporter: Update to 0.7.0.
Changes since 0.6.0:
[FEATURE] Automatically determine timeout from Prometheus's scrape_timeout
[FEATURE] Expose http version as metric
[FEATURE] Allow specifying with http versions classify as a success
[FEATURE] Add metric for regex or query response failure
[FEATURE] Expose configuration on /config
[ENHANCEMENT] Improve logging of tcp module errors