Fix version.
https://github.com/IoLanguage/io/pull/358
https://github.com/IoLanguage/io/commit/f828fee7fef0db8479f66896cbaf08ee390952f0
--- libs/iovm/source/IoVersion.h.orig
+++ libs/iovm/source/IoVersion.h
@@ -1,3 +1,3 @@
 #ifndef IO_VERSION_STRING
-#define IO_VERSION_STRING "20151111"
+#define IO_VERSION_STRING "20170906"
 #endif