GNU Radio 3.8 support

https://wiki.gnuradio.org/index.php/GNU_Radio_3.8_OOT_Module_Porting_Guide

Change-Id: I23dd638c8c48ed0a4b50559ce33fbd5e60b7dcbc
diff --git a/python/__init__.py b/python/__init__.py
index e2905e8..8241b01 100644
--- a/python/__init__.py
+++ b/python/__init__.py
@@ -31,9 +31,9 @@
     from dl import RTLD_GLOBAL as _RTLD_GLOBAL
 except ImportError:
     try:
-	from DLFCN import RTLD_GLOBAL as _RTLD_GLOBAL
+        from DLFCN import RTLD_GLOBAL as _RTLD_GLOBAL
     except ImportError:
-	pass
+        pass
 
 if _RTLD_GLOBAL != 0:
     _dlopenflags = sys.getdlopenflags()