It results in error "NSS error -5985 (PR_ADDRESS_NOT_SUPPORTED_ERROR)"
Disabled test 1470 for NSS builds and documented the restriction.
Reported-by: Dan Fandrich
Fixes #10723
Closes #10734
Since 7.50.2, unsupported schemes in proxy strings cause libcurl to return
error.
+
+curl built to use NSS cannot connect to a HTTPS server over a unix domain
+socket.
.SH RETURN VALUE
Returns CURLE_OK if proxies are supported, CURLE_UNKNOWN_OPTION if not, or
CURLE_OUT_OF_MEMORY if there was insufficient heap space.
<features>
proxy
unix-sockets
+!NSS
</features>
<server>
https