Fix F5 cookie in 10.x.x.x. (3.0)

The F5 cookie decoder doesn't detect IPs in the 10.x.x.x space for non-encrypted cookies. This fixes the regex pattern, see also
drwetter/F5-BIGIP-Decoder#4 and #2577

testssl.sh

@@ -3001,7 +3001,7 @@ sub_f5_bigip_check() {
           [[ -z "$cookievalue" ]] && break
           cookievalue=${cookievalue/;/}
           debugme echo $cookiename : $cookievalue
-          if grep -Eq '[0-9]{9,10}\.[0-9]{3,5}\.0000' <<< "$cookievalue"; then
+          if grep -Eq '[0-9]{8,10}\.[0-9]{3,5}\.0000' <<< "$cookievalue"; then
                ip="$(f5_ip_oldstyle "$cookievalue")"
                port="$(f5_port_decode $cookievalue)"
                out "${spaces}F5 cookie (default IPv4 pool member): "; pr_italic "$cookiename "; prln_svrty_medium "${ip}:${port}"