Corrections for a/an in code comments and documentation
diff --git a/PC/pyconfig.h b/PC/pyconfig.h
index d44173a..ac4f8f2 100644
--- a/PC/pyconfig.h
+++ b/PC/pyconfig.h
@@ -347,7 +347,7 @@
 #	define SIZEOF_FPOS_T 8
 #	define SIZEOF_HKEY 4
 #	define SIZEOF_SIZE_T 4
-	/* MS VS2005 changes time_t to an 64-bit type on all platforms */
+	/* MS VS2005 changes time_t to a 64-bit type on all platforms */
 #	if defined(_MSC_VER) && _MSC_VER >= 1400
 #	define SIZEOF_TIME_T 8
 #	else