Update problem_analysis.html

mancava una entry nella navbar dell'analisi del problema

Author: mikyll

Sprint1/resources/userDocs/problem_analysis.html

@@ -29,6 +29,7 @@
                 </div>
                 <a href="#Interactions">Interactions</a>
                 <div class="sidenavSubSection">
+                    <a href="Messages">Core-Business<br/>Messages</a>
                     <a href="#Smart-Device-Waste-Service">Smart Device &harr;<br/>Waste Service</a>
                     <a href="#Waste-Service-Transport-Trolley">Waste Service &harr;<br/>Transport Trolley</a>
                 </div>