patch-CMakeLists.txt

--- CMakeLists.txt.orig	2020-10-22 23:20:06 UTC
+++ CMakeLists.txt
@@ -2230,7 +2230,7 @@ if (NOT APPLE)
       DESTINATION ${PREFIX_DATA}/metainfo
       RENAME opencpn.appdata.xml
     )
-    install(FILES opencpn.1 DESTINATION ${PREFIX_DATA}/man/man1)
+    install(FILES opencpn.1 DESTINATION ${PREFIX_DATA}/../man/man1)
   endif (UNIX)
 
   IF(PACKAGE_FORMAT MATCHES "DEB")