Don't strip debug symbols.

Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -79,10 +79,6 @@ if (ENABLE_LTO)
     set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
 endif()
 
-if (NOT APPLE)
-    set(CMAKE_EXE_LINKER_FLAGS_RELEASE "${CMAKE_EXE_LINKER_FLAGS_RELEASE} -s")
-endif()
-
 if (WIN32)
     option(BUILD_STATIC "Statically link dependencies" OFF)
 endif()
