[Fix] KMComposerWin: Update encryption state when changing identities.

If we are in auto encryption mode, we need to retrigger the calulation
of the encryption state, as it is false by default. And will be
reenabled, if we have keys for every recipient.

src/autotests/kmcomposerwintest.cpp

@@ -221,7 +221,6 @@ void KMComposerWinTest::testChangeIdentity()
         QTimer::singleShot(50, &loop, SLOT(quit()));
         loop.exec();
         QCoreApplication::processEvents(QEventLoop::AllEvents);
-        QEXPECT_FAIL("", "Encryption state is not update correctly.", Continue);
         QCOMPARE(encryption->isVisible(), true);
         QCOMPARE(signature->isVisible(), true);
     }

src/editor/kmcomposerwin.cpp

@@ -3327,6 +3327,15 @@ void KMComposerWin::updateComposerAfterIdentityChanged(const KIdentityManagement
     // make sure the From and BCC fields are shown if necessary
     rethinkFields(false);
     setModified(wasModified);
+
+    // Update encryption status of all recipients, if encryption state is not set by user
+    const bool setByUser = mEncryptAction->property("setByUser").toBool();
+    if (!setByUser && ident.pgpAutoEncrypt()) {
+        const auto lst = mComposerBase->recipientsEditor()->lines();
+        for (auto line : lst) {
+            slotRecipientAdded(qobject_cast<MessageComposer::RecipientLineNG *>(line));
+        }
+    }
 }
 
 void KMComposerWin::slotSpellcheckConfig()