package/python3: security bump version to 3.7.3

Also remove upstream patch 0033.

Fixes the following security issues:

- bpo-36216: Changes urlsplit() to raise ValueError when the URL contains
  characters that decompose under IDNA encoding (NFKC-normalization) into
  characters that affect how the URL is parsed.

- bpo-35746: [CVE-2019-5010] Fix a NULL pointer deref in ssl module.  The
  cert parser did not handle CRL distribution points with empty DP or URI
  correctly.  A malicious or buggy certificate can result into segfault.
  Vulnerability (TALOS-2018-0758) reported by Colin Read and Nicolas Edet of
  Cisco.

- bpo-35121: Don’t send cookies of domain A without Domain attribute to
  domain B when domain A is a suffix match of domain B while using a
  cookiejar with http.cookiejar.DefaultCookiePolicy policy.  Patch by
  Karthikeyan Singaravelan.

For more details, see the changelog:
https://docs.python.org/3.7/whatsnew/changelog.html#python-3-7-3-final

Signed-off-by: Adam Duskett <Aduskett@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 6afc83b60f)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/python3/python3.mk

@@ -5,7 +5,7 @@
 ################################################################################
 
 PYTHON3_VERSION_MAJOR = 3.7
-PYTHON3_VERSION = $(PYTHON3_VERSION_MAJOR).2
+PYTHON3_VERSION = $(PYTHON3_VERSION_MAJOR).3
 PYTHON3_SOURCE = Python-$(PYTHON3_VERSION).tar.xz
 PYTHON3_SITE = https://python.org/ftp/python/$(PYTHON3_VERSION)
 PYTHON3_LICENSE = Python-2.0, others