Put man pages where they belong.

Index: setupbase.py
--- setupbase.py.orig
+++ setupbase.py
@@ -93,7 +93,7 @@ def find_data_files():
     Just man pages at this point.
     """
 
-    if "freebsd" in sys.platform:
+    if "freebsd" or "openbsd" in sys.platform:
         manpagebase = Path("man") / "man1"
     else:
         manpagebase = Path("share") / "man" / "man1"
