mesh: Fix changing Relay state from Not Supported (0x02)
mesh: Fix changing Relay state from Not Supported (0x02)

If the Relay state is set to Not Supported (0x02) the Config Relay Set
message should not change the state, rather just return its current
value.

X-Original-Commit: b0bd10f423eb3d447165fc54c7ea394bf3ac9377

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble