Removed trailing whitespace

docs/solidity-by-example.rst

@@ -15,7 +15,7 @@ a lot of Solidity's features. It implements a voting
 contract. Of course, the main problems of electronic
 voting is how to assign voting rights to the correct
 persons and how to prevent manipulation. We will not
-solve all problems here, but at least we will show 
+solve all problems here, but at least we will show
 how delegated voting can be done so that vote counting
 is **automatic and completely transparent** at the
 same time.
@@ -125,7 +125,7 @@ of votes.
             Voter delegate = voters[to];
             if (delegate.voted) {
                 // If the delegate already voted,
-                // directly add to the number of votes 
+                // directly add to the number of votes
                 proposals[delegate.vote].voteCount += sender.weight;
             }
             else {