lib: Remove useless empty constructors

src/lib/common/DataDirectories.h

@@ -32,9 +32,6 @@ public:
     static const std::string& systemconfig(const std::string& path);
 
 private:
-    // static class
-    DataDirectories() {}
-
     static std::string _profile;
     static std::string _global;
     static std::string _systemconfig;

src/lib/common/PathUtilities.h

@@ -24,8 +24,4 @@ class PathUtilities
 public:
     static std::string basename(const std::string& path);
     static std::string concat(const std::string& left, const std::string& right);
-
-private:
-    // static class
-    PathUtilities() {}
 };

src/lib/platform/ImmuneKeysReader.h

@@ -27,8 +27,4 @@ class ImmuneKeysReader
 {
 public:
     static bool get_list(const char * const path, std::vector<DWORD> &keys, std::string &badLine);
-
-private:
-    // static class
-    explicit ImmuneKeysReader() {}
 };