Change time resolution of reco_delay from second to millionseconds

Per gnutls anti replay issue, it needs millionsecond time delay for
improve the fail rate.

From test result of #6712, this can improve the fail rate from 4%
to 92%.

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 02ee7cf..304d10c 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -424,7 +424,7 @@
     "    reconnect=%%d        number of reconnections using session resumption\n" \
     "                        default: 0 (disabled)\n"       \
     "    reco_server_name=%%s  default: NULL\n"             \
-    "    reco_delay=%%d       default: 0 seconds\n"         \
+    "    reco_delay=%%d       default: 0 millionseconds\n"         \
     "    reco_mode=%%d        0: copy session, 1: serialize session\n" \
     "                        default: 1\n"      \
     "    reconnect_hard=%%d   default: 0 (disabled)\n"      \
@@ -3184,7 +3184,7 @@
 
 #if defined(MBEDTLS_TIMING_C)
         if( opt.reco_delay > 0 )
-            mbedtls_net_usleep( 1000000 * opt.reco_delay );
+            mbedtls_net_usleep( 1000 * opt.reco_delay );
 #endif
 
         mbedtls_printf( "  . Reconnecting with saved session..." );