conky/conky-cli: fix build with gcc7

srcpkgs/conky-cli/template

@@ -1,7 +1,7 @@
 # Template file for 'conky-cli'
 pkgname=conky-cli
 version=1.10.6
-revision=1
+revision=2
 wrksrc="${pkgname/-cli/}-${version}"
 build_style=cmake
 configure_args="

srcpkgs/conky/patches/gcc7.patch

@@ -0,0 +1,12 @@
+See https://git.archlinux.org/svntogit/packages.git/tree/trunk/gcc7.patch?h=packages/conky
+diff -Naur old/src/luamm.hh new/src/luamm.hh
+--- src/luamm.hh	2016-12-04 05:13:57.000000000 -1000
++++ src/luamm.hh	2017-11-21 09:11:20.993164069 -1000
+@@ -28,6 +28,7 @@
+ #include <exception>
+ #include <stdexcept>
+ #include <string>
++#include <functional>
+ 
+ #include <lua.hpp>
+ 

srcpkgs/conky/template

@@ -1,7 +1,7 @@
 # Template file for 'conky'
 pkgname=conky
 version=1.10.6
-revision=1
+revision=2
 build_style=cmake
 configure_args="
  -DCMAKE_BUILD_TYPE=Release -DMAINTAINER_MODE=ON -DDOC_PATH=share/${pkgname}