python3: Update to version 3.7.4

- Update setuptools to 40.8.0
- Update pip to 19.0.3
- Refreshed patches
- Removed 4 patches (2 of them was included in 3.7.3 and other two are
included in this release)

Makefile python3:
- Move PKG_MAINTAINER above PKG_LICENSE

Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>

lang/python/python3/patches/008-distutils-use-python-sysroot.patch

@@ -20,8 +20,6 @@ Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  Lib/distutils/sysconfig.py         | 15 +++++++++++----
  2 files changed, 15 insertions(+), 5 deletions(-)
 
-diff --git a/Lib/distutils/command/build_ext.py b/Lib/distutils/command/build_ext.py
-index 74de782d8a..d0c847b365 100644
 --- a/Lib/distutils/command/build_ext.py
 +++ b/Lib/distutils/command/build_ext.py
 @@ -234,7 +234,10 @@ class build_ext(Command):
@@ -36,8 +34,6 @@ index 74de782d8a..d0c847b365 100644
              else:
                  # building python standard extensions
                  self.library_dirs.append('.')
-diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
-index 2bcd1dd288..422c13fa4f 100644
 --- a/Lib/distutils/sysconfig.py
 +++ b/Lib/distutils/sysconfig.py
 @@ -17,10 +17,17 @@ import sys
@@ -62,6 +58,3 @@ index 2bcd1dd288..422c13fa4f 100644
  
  # Path to the base directory of the project. On Windows the binary may
  # live in project/PCbuild/win32 or project/PCbuild/amd64.
--- 
-2.13.5
-