minor #383 Update sl translation (peterkokot)

This PR was merged into the master branch.

Discussion
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Update sl translation

This patch updates Slovenian (sl_SI) translation according to the English.

Thanks for considering merging it.

Commits
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f9eb667 Update sl translation

app/Resources/translations/messages.sl.xliff

@@ -219,6 +219,10 @@
                 <source>menu.toggle_nav</source>
                 <target>Preklop navigacije</target>
             </trans-unit>
+            <trans-unit id="menu.choose_language">
+                <source>menu.choose_language</source>
+                <target>Izbira jezika</target>
+            </trans-unit>
             <trans-unit id="menu.post_list">
                 <source>menu.post_list</source>
                 <target>Seznam objav</target>