misc: remove Qt version macros wrapping metatype declarations

We've committed to Qt 5.15 as a minumum requirement for this client
for now.

Gitlab: #581
Change-Id: If3fd6a7bcb4a02dec31ad4e26b41f7650230cc28

src/accountadapter.h

@@ -123,6 +123,4 @@ private:
     QMetaObject::Connection contactAddedConnection_;
     QMetaObject::Connection addedToConferenceConnection_;
 };
-#if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
 Q_DECLARE_METATYPE(AccountAdapter *)
-#endif

src/clientwrapper.h

@@ -94,6 +94,4 @@ signals:
     void contactModelChanged();
     void deviceModelChanged();
 };
-#if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
 Q_DECLARE_METATYPE(ClientWrapper *)
-#endif

src/lrcinstance.h

@@ -472,6 +472,4 @@ private:
     MapStringString contentDrafts_;
     MapStringString lastConferencees_;
 };
-#if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
 Q_DECLARE_METATYPE(LRCInstance *)
-#endif

src/rendermanager.h

@@ -277,6 +277,4 @@ private:
      */
     AVModel &avModel_;
 };
-#if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
 Q_DECLARE_METATYPE(RenderManager *)
-#endif

src/settingsadaptor.h

@@ -238,6 +238,4 @@ public:
     Q_INVOKABLE void set_FileUserCert(QString text);
     Q_INVOKABLE void set_FilePrivateKey(QString text);
 };
-#if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
 Q_DECLARE_METATYPE(SettingsAdaptor *)
-#endif

src/utils.h

@@ -560,6 +560,4 @@ public:
 private:
     QClipboard *clipboard_;
 };
-#if QT_VERSION >= QT_VERSION_CHECK(5, 8, 0)
 Q_DECLARE_METATYPE(UtilsAdapter *)
-#endif