fixed bug in write method

rsmcore/session.cc

@@ -236,9 +236,10 @@ bool SFTPFile::isOpen() { return (p->file != nullptr); }
 // on error, returns < 0 and ssh and sftp session errors are set
 ssize_t SFTPFile::write(QString str)
 {
-  const char* buf  = str.toStdString().c_str();
-  size_t count     = strlen(buf);
-  ssize_t nwritten = sftp_write(p->file, buf, count);
+  std::string stdStr = str.toStdString();
+  const char* buf    = stdStr.c_str();
+  size_t count       = strlen(buf);
+  ssize_t nwritten   = sftp_write(p->file, buf, count);
   return nwritten;
 }