add DI annotations to WebInitializer

add DI annotations to WebInitializer

I need this in https://github.com/vorburger/opendaylight-simple to fix:

com.google.inject.CreationException: Unable to create injector, see the
following errors:

1) Could not find a suitable constructor in
org.opendaylight.aaa.shiro.web.env.WebInitializer. Classes must have
either one (and only one) constructor annotated with @Inject or a
zero-argument constructor that is not private.
  at org.opendaylight.aaa.shiro.web.env.WebInitializer.class(WebInitializer.java:39)
  at org.opendaylight.infrautils.simple.DiagStatusWiring.configure(DiagStatusWiring.java:30)

1 error
	at com.google.inject.internal.Errors.throwCreationExceptionIfErrorsExist(Errors.java:470)
	at com.google.inject.internal.InternalInjectorCreator.initializeStatically(InternalInjectorCreator.java:155)
	at com.google.inject.internal.InternalInjectorCreator.build(InternalInjectorCreator.java:107)
	at com.google.inject.Guice.createInjector(Guice.java:99)
	at org.opendaylight.infrautils.inject.guice.testutils.GuiceRule.setUpGuice(GuiceRule.java:93)
	at org.opendaylight.infrautils.inject.guice.testutils.GuiceRule$1.evaluate(GuiceRule.java:83)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)

Change-Id: Icda5a93e6943336b45c0a4683de04a55a8e64fe4
Signed-off-by: Michael Vorburger <vorburger@redhat.com>