fix bug for solaris.

dnsapi/deploy: remove POSIX character classes from sed/grep patterns

Solaris /usr/bin/sed and /usr/bin/grep parse [[:space:]] etc. as a
literal bracket set and silently mis-match. Replace with [ ]* for
JSON matching, a printf-tab bracket for user-input trimming, and
[0-9] for digits; also drop GNU-only sed -r/-E in rage4, selfhost
and selectel, and reuse _strip_blank_lines in byteplus_alb.

deploy/byteplus_alb.sh

@@ -163,8 +163,8 @@ byteplus_alb_deploy() {
   # ── 3. Read cert and key ─────────────────────────────────────────────────────
   # BytePlus requires NO blank lines between PEM blocks in the certificate chain
 
-  _public_key=$(sed '/^[[:space:]]*$/d' "$_cfullchain" | tr -d '\r')
-  _private_key=$(sed '/^[[:space:]]*$/d' "$_ckey" | tr -d '\r')
+  _public_key=$(_strip_blank_lines <"$_cfullchain" | tr -d '\r')
+  _private_key=$(_strip_blank_lines <"$_ckey" | tr -d '\r')
 
   if [ -z "$_public_key" ] || [ -z "$_private_key" ]; then
     _err "Failed to read certificate or key file."