repair version parsing from Makefile

Makefile

@@ -2,7 +2,7 @@ PYTHON?=python
 PYTHON3?=python3
 SETUPFLAGS=
 PACKAGENAME=fastrlock
-VERSION=$(shell python -c 'import re; f=open("setup.py"); print(re.search("VERSION\s*=\s*(.+)", f.read()).group(1).strip("\x27")); f.close()')
+VERSION=$(shell python -c 'import re; f=open("fastrlock/__init__.py"); print(re.search("__version__\s*=\s*[\x27\x22](.+)[\x27\x22]", f.read()).group(1)); f.close()')
 
 PYTHON_WITH_CYTHON=$(shell $(PYTHON)  -c 'import Cython.Compiler' >/dev/null 2>/dev/null && echo " --with-cython" || true)
 PY3_WITH_CYTHON=$(shell $(PYTHON3) -c 'import Cython.Compiler' >/dev/null 2>/dev/null && echo " --with-cython" || true)