RemoteLinux: Shut down an unresponsive SSH master connection

Otherwise, all subsequent ssh operations will silently fail.

Fixes: QTCREATORBUG-29982
Change-Id: I781aafcf408a9cb216f632e2beef92ec38652f57
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/plugins/remotelinux/linuxdevice.cpp

@@ -185,6 +185,7 @@ void SshSharedConnection::connectToHost()
     });
 
     QStringList args = QStringList{"-M", "-N", "-o", "ControlPersist=no",
+            "-o", "ServerAliveInterval=10", // TODO: Make configurable?
             "-o", "PermitLocalCommand=yes", // Enable local command
             "-o", "LocalCommand=echo"}      // Local command is executed after successfully
                                             // connecting to the server. "echo" will print "\n"