Fix LibreSSL returns 0 on failure

In some cases LibreSSL's s_client returns a status of 0 even when the connection fails. In the cases in which this happens there always seems to be a line in the output of the form "SSL handshake has read 0 bytes and written ... bytes". The commit fixes the problem by not treating a connection as successful if the string "SSL handshake has read 0 bytes and written" is present.

testssl.sh

@@ -7823,7 +7823,7 @@ sclient_connect_successful() {
      local re='Master-Key: ([^\
 ]*)'
 
-     [[ $1 -eq 0 ]] && connect_success=true
+     [[ $1 -eq 0 ]] && [[ ! "$server_hello" =~ SSL\ handshake\ has\ read\ 0\ bytes\ and\ written ]] && connect_success=true
      if ! "$connect_success" && [[ "$server_hello" =~ $re ]]; then
           [[ -n "${BASH_REMATCH[1]}" ]] && connect_success=true
      fi
@@ -21825,7 +21825,7 @@ sclient_auth() {
 ]*)'
      local connect_success=false
 
-     [[ $1 -eq 0 ]] && connect_success=true
+     [[ $1 -eq 0 ]] && [[ ! "$server_hello" =~ SSL\ handshake\ has\ read\ 0\ bytes\ and\ written ]] && connect_success=true
 
      ! "$connect_success" && [[ "$server_hello" =~ $re ]] && \
           [[ -n "${BASH_REMATCH[1]}" ]] && connect_success=true