jimtcl: update to master branch 20211108

Today's version of jimtcl includes a fix for autoconf >= 2.70 and
a minor fix for warnings with GCC 11.
To prepare for next jimtcl 0.81, let's merge and test the updated
master branch.

Change-Id: I455cc708f7d4786461978e38b6ac71816e2c9825
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6674
Tested-by: jenkins

diff --git a/jimtcl b/jimtcl
index 2d66360c61d2a89d4008e8bad12ae3aa5f0331e2..70b007b63669a709b0e8aef34a22658047815cc2 160000 (submodule)
--- a/jimtcl
+++ b/jimtcl
@@ -1 +1 @@
-Subproject commit 2d66360c61d2a89d4008e8bad12ae3aa5f0331e2
+Subproject commit 70b007b63669a709b0e8aef34a22658047815cc2