conan: cmake generator produces invalid conanbuildinfo.cmake when there are multiple CPPFLAGS

I have a package (GoogleTest) that is passing more than one flag to its consumers via cpp_info.cppflags. In the generated conanbuildinfo.cmake, the line set(CONAN_CXX_FLAGS_GOOGLETEST "-DGTEST_USE_OWN_TR1_TUPLE=1 -DGTEST_LINKED_AS_SHARED_LIBRARY=1") causes CMake to issue a compilation command of the form:

/longest_path/c++    -isystem /longer_path/include  -stdlib=libc++ -O3 -DNDEBUG -fPIE   "-Wall -Werror -DGTEST_USE_OWN_TR1_TUPLE=1 -DGTEST_LINKED_AS_SHARED_LIBRARY=1" -std=c++11 -o CMakeFiles/main.dir/main.cpp.o -c /long_path/main.cpp

It looks like the CMakeFiles/main.dir/flags.make file contains:

CXX_FLAGS =  -stdlib=libc++ -O3 -DNDEBUG -fPIE   "-Wall -Werror -DGTEST_USE_OWN_TR1_TUPLE=1 -DGTEST_LINKED_AS_SHARED_LIBRARY=1" -std=c++11

I believe the fix is to remove the double quotes from the generated CMake set command.