Removed useless semicolon

Cause an error when the doc is generated

Babylon/Culling/babylon.boundingSphere.ts

@@ -10,7 +10,7 @@
         constructor(public minimum: Vector3, public maximum: Vector3) {
             var distance = BABYLON.Vector3.Distance(minimum, maximum);
 
-            this.center = BABYLON.Vector3.Lerp(minimum, maximum, 0.5);;
+            this.center = BABYLON.Vector3.Lerp(minimum, maximum, 0.5);
             this.radius = distance * 0.5;
 
             this.centerWorld = BABYLON.Vector3.Zero();
@@ -61,4 +61,4 @@
         }
 
     }
-} 
+}