Fix SC_EXIT_CODE_NONE value

The exit code on windows is stored in a DWORD, an unsigned long:
<https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-dtyp/262627d8-3418-4627-9218-4ffe110850b2>

Use the max value of this type for SC_EXIT_CODE_NONE.

app/src/util/process.h

@@ -15,7 +15,7 @@
 // <https://stackoverflow.com/a/44383330/1987178>
 # define SC_PRIsizet "Iu"
 # define SC_PROCESS_NONE NULL
-# define SC_EXIT_CODE_NONE -1u // max value as unsigned
+# define SC_EXIT_CODE_NONE -1UL // max value as unsigned long
   typedef HANDLE sc_pid;
   typedef DWORD sc_exit_code;
   typedef HANDLE sc_pipe;