My intention was to log this message only in verbose mode, but it turns out print_msg always logs the message. We need to use print_error instead. This is a bit counterintuitive to me, as in other logging frameworks the severity of errors is higher than the severity of info messages and debug messages.
This antipattern of using print_error for debbuging logs will be cleaned out of the codebase when I eventually backport https://github.com/spesmilo/electrum/commit/3385a94753af2d93913ee9e9d67d18627c9c8f9e