Fixing lecture 22 link

Author: marpierc

lectures.html

@@ -584,7 +584,7 @@ <h6 class="card-subtitle mb-2 text-muted">April 28th, 2020</h6>
                               Bitcoin and Blockchain basics
                             </li>
                         </ul>
-                        <a href="http://courses.airavata.org/slides/Spring2020-pring2020-BitcoinBlockchainLedgers.pdf"
+                        <a href="http://courses.airavata.org/slides/Spring2020-BitcoinBlockchainLedgers.pdf"
                            class="btn btn-sm btn-link-iu-crimson">Introduction to the Bitcoin</a>
                     </div>
                 </div>