rtlsdr device stops and doesn't restart when GPS first sets system clock

[jbrzusto]

this is a show-stopper: we need devices to deal gracefully with the first setting of the system clock from GPS, as this will step time from 2000-01-01

Symptoms:

• in VAH, device marked as not running.
• rtl_tcp still running
• killing rtl_tcp does not restore functionality, even though rtl_tcp gets restarted
• killing rtl_tcp and VAH does not restore functionality, even though both are restarted
• also, likely due to the same cause, simply killing rtl_tcp leads to a new instance thereof which
• funcubes are not subject to this bug

[jbrzusto]

/tmp/rtlsdr-X:Y.sock is being unlinked while still open, leading to two such sockets in existence, one outside the filesystem.