Un-break building under arm64

The -msse option is specific to x86_64, it does not build under arm64.

Author: Alex Roitman

setup.py

@@ -16,7 +16,7 @@
 if sys.platform == "win32":
 	cflags = ["/O2"]
 else:
-	cflags = ["-O3", "-msse4.2"]
+	cflags = ["-O3", "-march=native"]
 
 extensions = [Extension(
 	"metrohash",