dstat: patch to silence collections warnings

Development on dstat is dead so whenever Python makes good on their
threat of removing direct access to collections.Sequence it will fail.

srcpkgs/dstat/patches/dstat.patch

@@ -0,0 +1,20 @@
+--- dstat.orig  2020-11-21 17:50:21.000000000 -0800
++++ dstat       2021-02-04 22:50:28.970723977 -0800
+@@ -19,7 +19,7 @@
+ from __future__ import absolute_import, division, generators, print_function
+ __metaclass__ = type
+ 
+-import collections
++import collections.abc
+ import fnmatch
+ import getopt
+ import getpass
+@@ -512,7 +512,7 @@
+                 scale = self.scales[i]
+             else:
+                 scale = self.scale
+-            if isinstance(self.val[name], collections.Sequence) and not isinstance(self.val[name], six.string_types):
++            if isinstance(self.val[name], collections.abc.Sequence) and not isinstance(self.val[name], six.string_types):
+                 line = line + cprintlist(self.val[name], ctype, self.width, scale)
+                 sep = theme['frame'] + char['colon']
+                 if i + 1 != len(self.vars):

srcpkgs/dstat/template

@@ -1,7 +1,7 @@
 # Template file for 'dstat'
 pkgname=dstat
 version=0.7.4
-revision=3
+revision=4
 makedepends="python3"
 depends="python3-six"
 short_desc="Versatile tool for generating system resource statistics"