Apply all the clang-tidy misc-* fixes

src/network/credentials_manager.cpp

@@ -98,7 +98,7 @@ bool BasicCredentialsManager::try_to_open_one_ca_bundle(const std::vector<std::s
               // because the certificate is signed by an issuer that was ignored.
               try {
                   Botan::X509_Certificate cert(bundle);
-                  BasicCredentialsManager::certificate_store.add_certificate(std::move(cert));
+                  BasicCredentialsManager::certificate_store.add_certificate(cert);
                 } catch (const Botan::Decoding_Error& error) {
                   continue;
                 }

src/network/tcp_socket_handler.cpp

@@ -42,7 +42,6 @@ namespace
 using namespace std::string_literals;
 using namespace std::chrono_literals;
 
-namespace ph = std::placeholders;
 
 TCPSocketHandler::TCPSocketHandler(std::shared_ptr<Poller>& poller):
   SocketHandler(poller, -1),