Improve diagnostics for situations where Rails fails to boot

Author: andyw8

lib/ruby_lsp/ruby_lsp_rails/runner_client.rb

@@ -89,6 +89,7 @@ def initialize(outgoing_queue)
         @stderr.binmode
 
         initialize_response = T.must(read_response)
+
         @rails_root = T.let(initialize_response[:root], String)
         log_message("Finished booting Ruby LSP Rails server")
 
@@ -109,7 +110,7 @@ def initialize(outgoing_queue)
           end,
           Thread,
         )
-      rescue Errno::EPIPE, IncompleteMessageError
+      rescue Errno::EPIPE, IncompleteMessageError, MessageError
         raise InitializationError, @stderr.read
       end