patch 8.2.3799: edit test hangs or fails

Problem:    Edit test hangs or fails.
Solution:   Do not rethrow an exception when inside try/catch.
diff --git a/src/userfunc.c b/src/userfunc.c
index cc921f5..42fa492 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -3176,7 +3176,7 @@
 
     // When a :def function was called that uses :try an error would be turned
     // into an exception.  Need to give the error here.
-    if (need_rethrow && current_exception != NULL)
+    if (need_rethrow && current_exception != NULL && trylevel == 0)
     {
 	need_rethrow = FALSE;
 	handle_did_throw();