refactor constant definition

lib/server.js

@@ -34,7 +34,6 @@ var blockchainExplorerOpts;
 var messageBroker;
 var serviceVersion;
 
-var MAX_KEYS = 100;
 
 /**
  * Creates an instance of the Bitcore Wallet Service.
@@ -53,6 +52,8 @@ function WalletService() {
 };
 
 
+WalletService.MAX_KEYS = 100;
+
 // Time after which a Tx proposal can be erased by any copayer. in seconds
 WalletService.DELETE_LOCKTIME = 24 * 3600;
 
@@ -518,7 +519,7 @@ WalletService.prototype.addAccess = function(opts, cb) {
         return cb(Errors.NOT_AUTHORIZED);
       }
 
-      if (copayer.requestPubKeys.length > MAX_KEYS)
+      if (copayer.requestPubKeys.length > WalletService.MAX_KEYS)
         return cb(Errors.TOO_MANY_KEYS);
 
       self._addKeyToCopayer(wallet, copayer, opts, cb);