add back source and target

Author: vrozov

pom.xml

@@ -3022,6 +3022,8 @@
           <artifactId>maven-compiler-plugin</artifactId>
           <version>3.14.0</version>
           <configuration>
+            <source>${java.version}</source>
+            <target>${java.version}</target>
             <skipMain>true</skipMain> <!-- skip compile -->
             <skip>true</skip> <!-- skip testCompile -->
           </configuration>