Help with error "Bad owner or permissions on /home/username/.ssh/config"

I am able to run `~ $ssh pi@192.168.4.2` with no problem to connect passwordless to my RaspberryPi. When I try to run `connect_remote` on the client, I get the following error:
```
julia> connect_remote("pi@192.168.4.2", tunnel=:ssh)
┌ Warning: Tunnel output
│ errors =
│ Bad owner or permissions on /home/dennishb/.ssh/config
│
└ @ RemoteREPL ~/.julia/packages/RemoteREPL/BFqrB/src/tunnels.jl:31
┌ Error: Exceeded maximum socket connection attempts
└ @ RemoteREPL ~/.julia/packages/RemoteREPL/BFqrB/src/tunnels.jl:87
ERROR: IOError: connect: connection refused (ECONNREFUSED)
Stacktrace:
[1] wait_connected(x::Sockets.TCPSocket)
@ Sockets ~/.julia/juliaup/julia-1.9.1+0.x64.linux.gnu/share/julia/stdlib/v1.9/Sockets/src/Sockets.jl:528
[2] connect
@ ~/.julia/juliaup/julia-1.9.1+0.x64.linux.gnu/share/julia/stdlib/v1.9/Sockets/src/Sockets.jl:563 [inlined]
[3] connect
@ ~/.julia/juliaup/julia-1.9.1+0.x64.linux.gnu/share/julia/stdlib/v1.9/Sockets/src/Sockets.jl:549 [inlined]
[4] connect_via_tunnel(host::String, port::Int64; retry_timeout::Int64, tunnel::Symbol, ssh_opts::Cmd, region::Nothing, namespace::Nothing)
@ RemoteREPL ~/.julia/packages/RemoteREPL/BFqrB/src/tunnels.jl:80
[5] setup_connection!(conn::RemoteREPL.Connection)
@ RemoteREPL ~/.julia/packages/RemoteREPL/BFqrB/src/client.jl:138
[6] #Connection#38
@ ~/.julia/packages/RemoteREPL/BFqrB/src/client.jl:128 [inlined]
[7] Connection
@ ~/.julia/packages/RemoteREPL/BFqrB/src/client.jl:120 [inlined]
[8] connect_remote(host::String, port::Int64; tunnel::Symbol, ssh_opts::Cmd, region::Nothing, namespace::Nothing)
@ RemoteREPL ~/.julia/packages/RemoteREPL/BFqrB/src/client.jl:487
[9] top-level scope
@ REPL[4]:1
```
on the server (Pi), there is a Julia process running, connected with SSH, with `using RemoteREPL` having been run. It may be noteworthy that I am using 1.6 on the server (Pi), and 1.9 on the client, which could be the problem. However, the error message indicates that something else is the problem.

The contents of `.ssh.config` (on the server side) were
```
Host 192.168.4.2
HostName 192.168.4.2
User pi
```
I do not recall having configured this manually. I tried adding the lines
```
Host 192.168.4.2
User pi
IdentityFile ~/.ssh/id_rsa
```
to the .ssh/config file on the client, but that did not change anything.

Any help on what may have gone wrong?