fix #2828 mailto compliant to RFC6068

This fix removes the space between "mailto:" and the email address to
make the contact attribute compliant to RFC6068.

acme.sh

@@ -3417,13 +3417,13 @@ _regAccount() {
   if [ "$ACME_VERSION" = "2" ]; then
     regjson='{"termsOfServiceAgreed": true}'
     if [ "$ACCOUNT_EMAIL" ]; then
-      regjson='{"contact": ["mailto: '$ACCOUNT_EMAIL'"], "termsOfServiceAgreed": true}'
+      regjson='{"contact": ["mailto:'$ACCOUNT_EMAIL'"], "termsOfServiceAgreed": true}'
     fi
   else
     _reg_res="$ACME_NEW_ACCOUNT_RES"
     regjson='{"resource": "'$_reg_res'", "terms-of-service-agreed": true, "agreement": "'$ACME_AGREEMENT'"}'
     if [ "$ACCOUNT_EMAIL" ]; then
-      regjson='{"resource": "'$_reg_res'", "contact": ["mailto: '$ACCOUNT_EMAIL'"], "terms-of-service-agreed": true, "agreement": "'$ACME_AGREEMENT'"}'
+      regjson='{"resource": "'$_reg_res'", "contact": ["mailto:'$ACCOUNT_EMAIL'"], "terms-of-service-agreed": true, "agreement": "'$ACME_AGREEMENT'"}'
     fi
   fi
 
@@ -3503,7 +3503,7 @@ updateaccount() {
 
   if [ "$ACME_VERSION" = "2" ]; then
     if [ "$ACCOUNT_EMAIL" ]; then
-      updjson='{"contact": ["mailto: '$ACCOUNT_EMAIL'"]}'
+      updjson='{"contact": ["mailto:'$ACCOUNT_EMAIL'"]}'
     fi
   else
     # ACMEv1: Updates happen the same way a registration is done.