build: Set umask to 0022 for functional test suite

debian/changelog

@@ -1,6 +1,7 @@
 dpkg (1.18.12) UNRELEASED; urgency=medium
 
-  *
+  * Build system:
+    - Set umask to 0022 for functional test suite.
 
  -- Guillem Jover <guillem@debian.org>  Sun, 06 Nov 2016 05:03:23 +0100
 

t-func/atlocal.in

@@ -4,6 +4,9 @@ PATH="@abs_top_builddir@/dpkg-deb:@abs_top_builddir@/dpkg-split:@abs_top_builddi
 export PATH
 
 # Setup a sane environment
+
+umask 0022
+
 LC_ALL=C
 export LC_ALL