Installer: Upgrade Java Version to 10 to bypass Bytecode Mismatch during compilation

nbi/stub/ext/engine/nbproject/project.properties

@@ -67,8 +67,8 @@ javac.classpath=\
 # Space-separated list of extra javac options
 javac.compilerargs=
 javac.deprecation=false
-javac.source=1.6
-javac.target=1.6
+javac.source=10
+javac.target=10
 javac.test.classpath=\
     ${javac.classpath}:\
     ${build.classes.dir}:\