patch 8.2.4195: resizing terminal may cause to behave like CTRL-Z

Problem:    Resizing terminal may cause to behave like CTRL-Z.
Solution:   Set "got_tstp" only when in_mch_suspend is set. (Dorian Bivolaru,
            closes #9602, closes #9586)
diff --git a/src/os_unix.c b/src/os_unix.c
index 9930680..0af6016 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -868,10 +868,11 @@
 	signal(SIGTSTP, ignore_sigtstp ? SIG_IGN : SIG_DFL);
 	raise(sigarg);
     }
+    else
+	got_tstp = TRUE;
 
     // this is not required on all systems, but it doesn't hurt anybody
     signal(SIGTSTP, (RETSIGTYPE (*)())sig_tstp);
-    got_tstp = TRUE;
     SIGRETURN;
 }
 #endif
@@ -6414,6 +6415,7 @@
 	    if (got_tstp && !in_mch_suspend)
 	    {
 		exarg_T ea;
+
 		ea.forceit = TRUE;
 		ex_stop(&ea);
 		got_tstp = FALSE;