Remove DRM dependency

Remove DRM dependency

The drm download is removed.

	modified:   packaging/download-provider.spec
	modified:   src/agent/CMakeLists.txt
	modified:   src/agent/download-agent-debug.c
	modified:   src/agent/download-agent-dl-mgr.c
	modified:   src/agent/download-agent-file.c
	modified:   src/agent/download-agent-http-mgr.c
	modified:   src/agent/download-agent-http-queue.c
	deleted:    src/agent/download-agent-plugin-drm.c
	modified:   src/agent/download-agent-utils.c
	modified:   src/agent/include/download-agent-debug.h
	modified:   src/agent/include/download-agent-defs.h
	modified:   src/agent/include/download-agent-dl-mgr.h
	modified:   src/agent/include/download-agent-http-queue.h
	deleted:    src/agent/include/download-agent-plugin-drm.h
	modified:   src/agent/include/download-agent-utils.h