make vRPCCommands comment match property names

This is a real simple change to make the comments match the property names of `CRPCCommand`

Here is the diff, ignoring the whitespace:

```
$ git diff 44d7f4cbebd446f8f4a48ff9048d4549c0e2448a 3ab3b69837314926b76598a10c28e8305aa0acd2 --minimal -b
diff --git a/src/bitcoinrpc.cpp b/src/bitcoinrpc.cpp
index 7751e4c..70aeeb7 100644
--- a/src/bitcoinrpc.cpp
+++ b/src/bitcoinrpc.cpp
@@ -194,8 +194,8 @@ Value stop(const Array& params, bool fHelp)
 
 
 static const CRPCCommand vRPCCommands[] =
-{ //  name                      function                 safemd  unlocked
-  //  ------------------------  -----------------------  ------  --------
+{ //  name                      actor (function)         okSafeMode unlocked
+  //  ------------------------  -----------------------  ---------- --------
     { "help",                   &help,                   true,   true },
     { "stop",                   &stop,                   true,   true },
     { "getblockcount",          &getblockcount,          true,   false },

```