BUILD: Don't force the -g with CFLAGS

If a debug build is needed, use the following invocation of cmake:
    cmake -Bbuild -DCMAKE_BUILD_TYPE=Debug

Where:
* -B stands for the build folder
* -DCMAKE_BUILD_TYPE stands for the release type (Debug or Release)

CMakeLists.txt

@@ -24,8 +24,6 @@ find_library(AVFORMAT_LIBRARY avformat REQUIRED)
 
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fopenmp")
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp")
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g")
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g")
 
 # Grab all files
 file(GLOB Vivy_SRC