comment out PythonAiohttpServer test in travis

Author: wing328

pom.xml

@@ -1225,7 +1225,8 @@
                 </property>
             </activation>
             <modules>
-                <module>samples/server/petstore/python-aiohttp</module>
+                <!-- comment out below due to https://github.com/OpenAPITools/openapi-generator/issues/5235
+                <module>samples/server/petstore/python-aiohttp</module> -->
                 <!-- clients -->
                 <module>samples/client/petstore/bash</module>
                 <module>samples/client/petstore/c</module>