Another unzip flag update (-uo)

Change-Id: I07ff0231a0f0b9fcb9e774915728a79c3481c46b
diff --git a/lib/KorAP/XML/Archive.pm b/lib/KorAP/XML/Archive.pm
index 58a8731..c37164e 100644
--- a/lib/KorAP/XML/Archive.pm
+++ b/lib/KorAP/XML/Archive.pm
@@ -146,7 +146,7 @@
   my @init_cmd = (
     'unzip',          # Use unzip program
     '-qo',            # quietly overwrite all existing files
-    '-u',
+    '-uo',
     '-d', $target_dir # Extract into target directory
   );
 
@@ -222,7 +222,7 @@
   my @init_cmd = (
     'unzip',          # Use unzip program
     '-qo',            # quietly overwrite all existing files
-    '-u',
+    '-uo',
     '-d', $target_dir # Extract into target directory
   );
 
@@ -280,7 +280,7 @@
   my @init_cmd = (
     'unzip',          # Use unzip program
     '-qo',            # quietly overwrite all existing files
-    '-u',
+    '-uo',
     '-d', $target_dir # Extract into target directory
   );