[Common] Replace platform.linux_distribution function

As of python 3.5, this function is marked as deprecated.
So, [distro][1] is the one we will use (this package is listed at the
example package in the python's [docs][2]).

[1] https://pypi.org/project/distro/
[2] https://docs.python.org/3/library/platform.html#platform.dist

DEPENDS.md

@@ -30,6 +30,10 @@ All modules will require the [common](#common) section dependencies.
 - [Pillow] - Optional: Support for resizing tracker icons.
 - [dbus-python] - Optional: Show item location in filemanager.
 
+#### Linux and BSD
+
+- [distro] - Optional: OS platform information.
+
 #### Windows OS
 
 - [pywin32]
@@ -75,6 +79,7 @@ All modules will require the [common](#common) section dependencies.
 [pillow]: https://pypi.org/project/Pillow/
 [libtorrent]: https://libtorrent.org/
 [zope.interface]: https://pypi.org/project/zope.interface/
+[distro]: https://github.com/nir0s/distro
 [pywin32]: https://github.com/mhammond/pywin32
 [certifi]: https://pypi.org/project/certifi/
 [py2-ipaddress]: https://pypi.org/project/py2-ipaddress/

deluge/common.py

@@ -53,12 +53,17 @@ if platform.system() in ('Windows', 'Microsoft'):
 
     os.environ['SSL_CERT_FILE'] = where()
 
-# gi makes dbus available on Window but don't import it as unused.
+
 if platform.system() not in ('Windows', 'Microsoft', 'Darwin'):
+    # gi makes dbus available on Window but don't import it as unused.
     try:
         import dbus
     except ImportError:
         dbus = None
+    try:
+        import distro
+    except ImportError:
+        distro = None
 
 log = logging.getLogger(__name__)
 
@@ -266,8 +271,8 @@ def get_os_version():
     elif osx_check():
         os_version = list(platform.mac_ver())
         os_version[1] = ''  # versioninfo always empty.
-    elif linux_check():
-        os_version = platform.linux_distribution()
+    elif distro:
+        os_version = distro.linux_distribution()
     else:
         os_version = (platform.release(),)
 

requirements.txt

@@ -11,3 +11,4 @@ pywin32; sys_platform == 'win32'
 py2-ipaddress; sys_platform == 'win32' and python_version == '2'
 certifi; sys_platform == 'win32'
 zope.interface>=4.4.2
+distro; 'win' not in sys_platform

setup.py

@@ -551,6 +551,7 @@ install_requires = [
     "py2-ipaddress; sys_platform == 'win32' and python_version == '2'",
     "certifi; sys_platform == 'win32'",
     'zope.interface',
+    "distro; 'win' not in sys_platform",
 ]
 tests_require = ['pytest', 'pytest-twisted']