uitest: kill the LibreOffice instance if it ignores terminate request

Change-Id: I47c69878ebaa834eb75208ce8e5c26544e3e62bd
diff --git a/uitest/libreoffice/connection.py b/uitest/libreoffice/connection.py
index 7087ca8..bea7605 100644
--- a/uitest/libreoffice/connection.py
+++ b/uitest/libreoffice/connection.py
@@ -93,7 +93,22 @@ class OfficeConnection:
                    pass # ignore
            else:
                self.soffice.terminate()
            ret = self.soffice.wait()

            DEFAULT_SLEEP = 0.1
            time_ = 0
            while time_ < 5:
                time_ += DEFAULT_SLEEP
                ret_attr = self.soffice.poll()
                if ret_attr is not None:
                    break
                time.sleep(DEFAULT_SLEEP)

            ret = 0
            if ret_attr is None:
                ret = 1
                self.soffice.terminate()

            # ret = self.soffice.wait()
            self.xContext = None
            self.socket = None
            self.soffice = None