Delete qplaintextedit_sink_p.h

include/spdlog/sinks/qplaintextedit_sink_p.h

-// Copyright(c) 2015-present, Gabi Melman, mguludag and spdlog contributors.
-// Distributed under the MIT License (http://opensource.org/licenses/MIT)
-
-#pragma once
-
-#include <QObject>
-#include <QPlainTextEdit>
-
-namespace _spdlog_p {
-namespace _sinks_p {
-class qplaintextedit_sink_p : public QObject {
-    Q_OBJECT
-public:
-    qplaintextedit_sink_p(QPlainTextEdit *textedit = nullptr) {
-        if (textedit != nullptr) {
-            textedit_ = textedit;
-            connect(this, &qplaintextedit_sink_p::append_text, textedit_,
-                    &QPlainTextEdit::appendPlainText);
-        }
-    }
-
-    ~qplaintextedit_sink_p() {}
-
-    void append(const std::string &str) {
-        emit append_text(QString::fromStdString(str));
-    }
-
-signals:
-    void append_text(const QString &);
-
-private:
-    QPlainTextEdit *textedit_ = nullptr;
-};
-} // namespace _sinks_p
-} // namespace _spdlog_p