patch 8.0.1525: using :wqa exits even if a job runs in a terminal window

Problem:    Using :wqa exits even if a job runs in a terminal window. (Jason
            Felice)
Solution:   Check if a terminal has a running job. (closes #2654)

src/testdir/test_terminal.vim

@@ -712,6 +712,15 @@ func Test_terminal_wall()
   unlet g:job
 endfunc
 
+func Test_terminal_wqall()
+  let buf = Run_shell_in_terminal({})
+  call assert_fails('wqall', 'E948')
+  call Stop_shell_in_terminal(buf)
+  call term_wait(buf)
+  exe buf . 'bwipe'
+  unlet g:job
+endfunc
+
 func Test_terminal_composing_unicode()
   let save_enc = &encoding
   set encoding=utf-8