Fix crashing devicetest

Summary:
When running the test m_impl will be nullptr leading to a crash. This is because when running as a test no platform is loaded.
The fancy way to solve this would be to have a TestImpl, but I think this is enough.

Test Plan: Test passes now

Reviewers: #kde_connect, apol

Reviewed By: #kde_connect, apol

Subscribers: kdeconnect, #kde_connect

Tags: #kde_connect

Differential Revision: https://phabricator.kde.org/D13629

plugins/mousepad/mousepadplugin.cpp

@@ -82,7 +82,9 @@ bool MousepadPlugin::receivePacket(const NetworkPacket& np)
 
 void MousepadPlugin::connected() {
     NetworkPacket np(PACKET_TYPE_MOUSEPAD_KEYBOARDSTATE);
+    if (m_impl) {
         np.set<bool>(QStringLiteral("state"), m_impl->hasKeyboardSupport());
+    }
     sendPacket(np);
 }
 

tests/devicetest.cpp

@@ -94,6 +94,9 @@ void DeviceTest::testPairedDevice()
 
 void DeviceTest::testUnpairedDevice()
 {
+    KdeConnectConfig* kcc = KdeConnectConfig::instance();
+    kcc->removeTrustedDevice(deviceId);
+
     LanLinkProvider linkProvider;
     QSslSocket socket;
     LanDeviceLink* link = new LanDeviceLink(deviceId, &linkProvider, &socket, LanDeviceLink::Locally);