patch 8.2.0074: Python 3 unicode test someitmes fails

Problem:    Python 3 unicode test someitmes fails.
Solution:   Make 'termencoding' empty.  Correct number of error message.
diff --git a/src/change.c b/src/change.c
index f2dfc93..e5ac97b 100644
--- a/src/change.c
+++ b/src/change.c
@@ -1218,7 +1218,7 @@
     // If "count" is negative the caller must be doing something wrong.
     if (count < 1)
     {
-	siemsg("E950: Invalid count for del_bytes(): %ld", count);
+	siemsg("E292: Invalid count for del_bytes(): %ld", count);
 	return FAIL;
     }
 
diff --git a/src/testdir/test_python3.vim b/src/testdir/test_python3.vim
index 97f797e..cd5ac9c 100644
--- a/src/testdir/test_python3.vim
+++ b/src/testdir/test_python3.vim
@@ -170,11 +170,18 @@
 
 func Test_unicode()
   " this crashed Vim once
+  let save_tenc = &tenc
+  set tenc=
+
   set encoding=utf32
   py3 print('hello')
+
   set encoding=debug
   py3 print('hello')
+
   set encoding=euc-tw
   py3 print('hello')
+
   set encoding=utf8
+  let &tenc = save_tenc
 endfunc
diff --git a/src/version.c b/src/version.c
index c8df547..30f4465 100644
--- a/src/version.c
+++ b/src/version.c
@@ -743,6 +743,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    74,
+/**/
     73,
 /**/
     72,