CI: cleanup build warnings

Tests: fixed "unused const variable" warning
CMakeLists.txt: fixed deprecation warnings

src/console_commands.cpp

@@ -28,7 +28,7 @@
 #include "p2pool_api.h"
 #include "params.h"
 
-static constexpr char log_category_prefix[] = "ConsoleCommands ";
+LOG_CATEGORY(ConsoleCommands)
 
 static constexpr int DEFAULT_BACKLOG = 1;
 
@@ -123,6 +123,11 @@ void ConsoleCommands::on_shutdown()
 	uv_close(reinterpret_cast<uv_handle_t*>(m_stdin_handle), nullptr);
 }
 
+const char* ConsoleCommands::get_log_category() const
+{
+	return log_category_prefix;
+}
+
 typedef struct strconst {
 	const char *str;
 	size_t len;