Fix typo in German translation.

As pointed out by Robert Pollak, there's a typo in the German
translation of the compression preset option (-0 ... -9) help text.
"The compressor" translates to "der Komprimierer", and the genitive
form is "des Komprimierers". The old word makes no sense at all.

po/de.po

diff --git a/po/de.po b/po/de.po
index 31517f8..faba286 100644
--- a/po/de.po
+++ b/po/de.po
@@ -651,7 +651,7 @@
 "                      decompressor memory usage into account before using 7-9!"
 msgstr ""
 "  -0 .. -9              Kompressionseinstellung; Voreinstellung is 6. Beachten\n"
-"                        Sie den Speicherverbrauch des Komprimieres *und* des\n"
+"                        Sie den Speicherverbrauch des Komprimierers *und* des\n"
 "                        Dekomprimierers, wenn Sie 7-9 benutzen!"
 
 #: src/xz/message.c:1134