[network-manager-applet] docs: update copyright year

[Lubomir Rintel <lkundrak src gnome org>]

commit 068a9dbb50f2605185a26db363285c67f846ceae
Author: Lubomir Rintel <lkundrak v3 sk>
Date:   Mon Jul 23 12:22:53 2018 +0200

    docs: update copyright year

 libnma-docs.xml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/libnma-docs.xml b/libnma-docs.xml
index fdcfb385..ed264335 100644
--- a/libnma-docs.xml
+++ b/libnma-docs.xml
@@ -16,7 +16,8 @@
     </releaseinfo>
 
     <copyright>
- ]    <year>2017</year>
+      <year>2017</year>
+      <year>2018</year>
       <holder>The &package_tarname; Authors</holder>
     </copyright>