Correct repetition error / typo

Author: jerzybrzoska

README.md

@@ -161,7 +161,7 @@ would be a shame if Helium simply disappeared from the face of the earth. So I
 invested some time to modernize it and bring it into a state suitable for open
 source.
 
-Helium used to be available for both Java and Python. But I because I now only
+Helium used to be available for both Java and Python. But because I now only
 use it from Python, I didn't have time to bring the Java implementation up to
 speed as well. Similarly for Internet Explorer: Helium used to support it, but
 since I have no need for it, I removed the (probably broken) old implementation.