try to avoid -Xlint:-serial

Author: Vladimir Kotal

pom.xml

@@ -201,7 +201,6 @@ Portions Copyright (c) 2018, Chris Fraire <[email protected]>.
                     <compilerArgs>
                       <arg>-Xlint:all</arg>
                       <arg>-Werror</arg>
-                      <arg>-Xlint:-serial</arg>
                       <!-- meant for autogenerated sources -->
                       <arg>-Xlint:-auxiliaryclass</arg>
                       <arg>-Xlint:-fallthrough</arg>