Fix indentation bug

Author: dabeaz

Notes/05_Object_model/02_Classes_encapsulation.md

@@ -95,8 +95,8 @@ One approach: introduce accessor methods.
 class Stock:
     def __init__(self, name, shares, price):
         self.name = name
-	    self.set_shares(shares)
-	    self.price = price
+        self.set_shares(shares)
+        self.price = price
 
     # Function that layers the "get" operation
     def get_shares(self):