Remove -flto flag for GCC optimize=on. Apparently causes trouble with gcc 5.4

Author: paulromano

CMakeLists.txt

@@ -126,7 +126,7 @@ if(CMAKE_Fortran_COMPILER_ID STREQUAL GNU)
     list(APPEND ldflags -pg)
   endif()
   if(optimize)
-    list(APPEND f90flags -O3 -flto -fuse-linker-plugin)
+    list(APPEND f90flags -O3)
     list(APPEND cflags -O3)
   endif()
   if(openmp)