do not cache thumbprint for issues for ecc account key

acme.sh

@@ -834,9 +834,6 @@ _calcjwk() {
     return 1
   fi
 
-
-  
-  
   EC_SIGN=""
   if grep "BEGIN RSA PRIVATE KEY" "$keyfile" > /dev/null 2>&1 ; then
     _debug "RSA key"
@@ -2383,10 +2380,9 @@ issue() {
         return 1
       fi
       
-      if [ -z "$thumbprint" ] ; then
+
       accountkey_json=$(printf "%s" "$jwk" |  tr -d ' ' )
       thumbprint=$(printf "%s" "$accountkey_json" | _digest "sha256" | _urlencode)
-      fi
 
       entry="$(printf "%s\n" "$response" | _egrep_o  '[^\{]*"type":"'$vtype'"[^\}]*')"
       _debug entry "$entry"