test_ftp.rb: extend timeout for --jit-wait testing

to avoid random failures like
https://app.wercker.com/ruby/ruby/runs/mjit-test1/5be394b818310600284f2b50?step=5be394f1591ca800079b1329

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65620 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/net/ftp/test_ftp.rb

@@ -2171,7 +2171,7 @@ EOF
           begin
             ftp = Net::FTP.new
             ftp.resume = resume
-            ftp.read_timeout = RubyVM::MJIT.enabled? ? 1 : 0.2 # use large timeout for --jit-wait
+            ftp.read_timeout = RubyVM::MJIT.enabled? ? 5 : 0.2 # use large timeout for --jit-wait
             ftp.connect(SERVER_ADDR, server.port)
             ftp.login
             assert_match(/\AUSER /, commands.shift)