avoid mtree violation
--- router/CMakeLists.txt.orig	2019-05-03 04:55:18.000000000 -0700
+++ router/CMakeLists.txt	2019-09-18 12:39:48.000000000 -0700
@@ -87,7 +87,7 @@
 SET(ROUTER_LICENSE_FILE "${CMAKE_SOURCE_DIR}/router/LICENSE.router")
 SET(ROUTER_README_FILE "${CMAKE_SOURCE_DIR}/router/README.router")
 
-SET(DOC_DESTINATION ".")
+SET(DOC_DESTINATION "share/doc/percona")
 IF(NOT INSTALL_LAYOUT MATCHES "RPM")
   INSTALL(FILES
       ${ROUTER_LICENSE_FILE}