fix: allow capital letters on host match (#1117)

While matching [user@]host[:port], we previously did not allow capital
letters in host.

While this makes sense for a hostname, it does not make sense to make
that restriction for a host. Since this can match on both, we must widen
it to accept characters allowed in host.

Author: oneirocosm

pkg/remote/connutil.go

@@ -17,7 +17,7 @@ import (
 	"golang.org/x/crypto/ssh"
 )
 
-var userHostRe = regexp.MustCompile(`^([a-zA-Z0-9][a-zA-Z0-9._@\\-]*@)?([a-z0-9][a-z0-9.-]*)(?::([0-9]+))?$`)
+var userHostRe = regexp.MustCompile(`^([a-zA-Z0-9][a-zA-Z0-9._@\\-]*@)?([a-zA-Z0-9][a-zA-Z0-9.-]*)(?::([0-9]+))?$`)
 
 func ParseOpts(input string) (*SSHOpts, error) {
 	m := userHostRe.FindStringSubmatch(input)