refactor(registry,util): use default contructors instead of empty

src/libs/registry/docsetmetadata.cpp

@@ -32,10 +32,6 @@
 
 using namespace Zeal::Registry;
 
-DocsetMetadata::DocsetMetadata()
-{
-}
-
 DocsetMetadata::DocsetMetadata(const QJsonObject &jsonObject)
 {
     m_name = jsonObject[QStringLiteral("name")].toString();

src/libs/registry/docsetmetadata.h

@@ -35,7 +35,7 @@ namespace Registry {
 class DocsetMetadata
 {
 public:
-    explicit DocsetMetadata();
+    explicit DocsetMetadata() = default;
     explicit DocsetMetadata(const QJsonObject &jsonObject);
 
     void save(const QString &path, const QString &version);

src/libs/registry/searchquery.cpp

@@ -32,10 +32,6 @@ const char prefixSeparator = ':';
 const char keywordSeparator = ',';
 }
 
-SearchQuery::SearchQuery()
-{
-}
-
 SearchQuery::SearchQuery(QString query, const QStringList &keywords) :
     m_query(std::move(query))
 {

src/libs/registry/searchquery.h

@@ -35,7 +35,7 @@ namespace Registry {
 class SearchQuery
 {
 public:
-    explicit SearchQuery();
+    explicit SearchQuery() = default;
     explicit SearchQuery(QString query, const QStringList &keywords = QStringList());
 
     /// Creates a search query from a string. Single separator will be

src/libs/util/plist.cpp

@@ -27,11 +27,6 @@
 
 using namespace Zeal::Util;
 
-Plist::Plist() :
-    QHash<QString, QVariant>()
-{
-}
-
 bool Plist::read(const QString &fileName)
 {
     QScopedPointer<QFile> file(new QFile(fileName));

src/libs/util/plist.h

@@ -32,7 +32,7 @@ namespace Util {
 class Plist : public QHash<QString, QVariant>
 {
 public:
-    Plist();
+    Plist() = default;
 
     bool read(const QString &fileName);
     bool hasError() const;