JythonShell: Fix ClassNewInstance warning flagge by error prone

The following warning is issued on the base version by error prone:

warning: [ClassNewInstance] Class.newInstance() bypasses exception
checking; prefer getConstructor().newInstance()
      shell = console.newInstance();
                                 ^
    (see http://errorprone.info/bugpattern/ClassNewInstance)
  Did you mean 'shell = console.getConstructor().newInstance();'?

Change-Id: Ia3b474422965851ae1f64de4f2767179af33bf12

gerrit-pgm/src/main/java/com/google/gerrit/pgm/JythonShell.java

@@ -78,9 +78,14 @@ public class JythonShell {
         new Object[] {null, env});
 
     try {
-      shell = console.newInstance();
+      shell = console.getConstructor(new Class[] {}).newInstance();
       log.info("Jython shell instance created.");
-    } catch (InstantiationException | IllegalAccessException e) {
+    } catch (InstantiationException
+        | IllegalAccessException
+        | IllegalArgumentException
+        | InvocationTargetException
+        | NoSuchMethodException
+        | SecurityException e) {
       throw noInterpreter(e);
     }
     injectedVariables = new ArrayList<>();