Minor: fix grammar

I need to get my eyes checked...

Author: petertodd

README

@@ -5,7 +5,7 @@ This Python2/3 library provides an easy interface to the bitcoin data
 structures and protocol. The approach is low-level and "ground up", with a
 focus on providing tools to manipulate the internals of how Bitcoin works.
 
-"The Swiss Army Knife of Bitcoin protocol." - Wladimir J. van der Laan
+"The Swiss Army Knife of the Bitcoin protocol." - Wladimir J. van der Laan
 
 
 Requirements