fix: fix NPE for multicatch qualified exceptions

[bzEq]

fix #2860

[monperrus]

Awesome thanks. It would be super useful if you could add the corresponding test:

@Test
void testIssue2860() {
  Launcher launcher = new Launcher();
  launcher.addInputResource("D:\\untitled\\SomeModule");
  launcher.buildModel();
  ....
}

The goal is that CI fails ;-)

[monperrus]

reproduced, working on it.

[monperrus]

fixed locally, pushed, let's wait for CI