python3: merge python3-email into python3-urllib

As we're seeing in various test.sh scrip runs, importing 'email' fails
with not finding 'urllib' and vice-versa.

Then via a7e96ec91 ("python3-email: add python3-urllib as dependency")
I created a circular dependency.
So, might as well merge the two packages into one (named python3-urllib)
and updates all dependencies to pull python3-urllib.

Signed-off-by: Alexandru Ardelean <alex@shruggie.ro>

utils/borgbackup/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=borgbackup
 PKG_VERSION:=1.4.3
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PYPI_NAME:=borgbackup
 PKG_HASH:=79bbfa745d1901d685973584bd2d16a350686ddd176f6a2244490fb01996441f
@@ -32,7 +32,6 @@ define Package/borgbackup
   DEPENDS:= \
       +python3-light \
       +python3-codecs \
-      +python3-email \
       +python3-logging \
       +python3-lzma \
       +python3-msgpack \