update German translation

Author: corrados

src/res/translation/translation_de_DE.qm

@@ -547,12 +547,12 @@
     <message>
         <location filename="../../chatdlg.cpp" line="136"/>
         <source>Do you want to open the link</source>
-        <translation type="unfinished"></translation>
+        <translation>Willst du den Link</translation>
     </message>
     <message>
         <location filename="../../chatdlg.cpp" line="137"/>
         <source>in an external browser?</source>
-        <translation type="unfinished"></translation>
+        <translation>in einem externen Browser öffnen?</translation>
     </message>
 </context>
 <context>