Parse N[0-9]+[ ]* differently (PR #2263)

More general solution to skip N[0-9]+[ ]* in the parser as in #2218

Marlin/Marlin_main.cpp

@@ -5254,12 +5254,13 @@ void process_next_command() {
 
   // Sanitize the current command:
   //  - Skip leading spaces
-  //  - Bypass N...
+  //  - Bypass N[0-9][0-9]*[ ]*
   //  - Overwrite * with nul to mark the end
   while (*current_command == ' ') ++current_command;
   if (*current_command == 'N' && current_command[1] >= '0' && current_command[1] <= '9') {
-    while (*current_command != ' ' && *current_command != 'G' && *current_command != 'M' && *current_command != 'T') ++current_command;
-    while (*current_command == ' ') ++current_command;
+    current_command += 2; // skip N[0-9]
+    while (*current_command >= '0' && *current_command <= '9') ++current_command; // skip [0-9]*
+    while (*current_command == ' ') ++current_command; // skip [ ]*
   }
   char *starpos = strchr(current_command, '*');  // * should always be the last parameter
   if (starpos) *starpos = '\0';