Remove legacy start-class property from maven builds

complete/pom.xml

     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-        <start-class>hello.Application</start-class>
     </properties>
 
     <build>

initial/pom.xml

         </dependency>
     </dependencies>
 
-    <properties>
-        <start-class>hello.Application</start-class>
-    </properties>
 
     <build>
         <plugins>