Do not duplicate data installation

Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -174,12 +174,6 @@ if(WIN32)
     endif()
 endif()
 
-# Install data files
-install(DIRECTORY data/
-    DESTINATION ${CMAKE_INSTALL_DATADIR}/${PROJECT_NAME}
-    PATTERN "*.svn" EXCLUDE
-)
-
 # Install desktop file and icons on Linux
 if(UNIX AND NOT APPLE)
     install(FILES dunelegacy.desktop
@@ -230,4 +224,4 @@ else()
     set(CPACK_RPM_PACKAGE_GROUP "Amusements/Games")
 endif()
 
-include(CPack) 
\ No newline at end of file
+include(CPack) 
