packages: remove acl development library from build dependencies

Starting with commit v4.9-46-g681452b that removed all references
to acl.h, we no longer use acl development library.

* .travis.yml (addons.apt.packages): Remove libacl1-dev.
* strace.spec (BuildRequires): Remove libacl-devel.

.travis.yml

@@ -10,7 +10,6 @@ addons:
   apt:
     packages:
     - gcc-multilib
-    - libacl1-dev
 
 env:
   global:

strace.spec

@@ -6,7 +6,7 @@ License: BSD
 Group: Development/Debuggers
 URL: http://sourceforge.net/projects/strace/
 Source: http://downloads.sourceforge.net/strace/%{name}-%{version}.tar.xz
-BuildRequires: libacl-devel, time
+BuildRequires: time
 %ifarch x86_64
 # for experimental -k option
 BuildRequires: libunwind-devel