fixed typo in clusterByHubsize

lib/network/modules/Clustering.js

@@ -28,7 +28,7 @@ class ClusterEngine {
     if (hubsize === undefined) {
       hubsize = this._getHubSize();
     }
-    else if (tyepof(hubsize) === "object") {
+    else if (typeof(hubsize) === "object") {
       options = this._checkOptions(hubsize);
       hubsize = this._getHubSize();
     }