fix space in commons exec

README.md

@@ -713,7 +713,7 @@ A curated list of awesome Java frameworks, libraries and software.
 - [Collections](http://commons.apache.org/proper/commons-collections) - Extends or augments the Java Collections Framework.
 - [DBCP](http://commons.apache.org/proper/commons-dbcp) - Database connection pooling services.
 - [Math](http://commons.apache.org/proper/commons-math) - Lightweight, self-contained mathematics and statistics components.
-- [Exec by Apache Commons] (http://commons.apache.org/proper/commons-exec) - API for dealing with external process execution and environment management in Java.
+- [Exec by Apache Commons](http://commons.apache.org/proper/commons-exec) - API for dealing with external process execution and environment management in Java.
 - [Exec by Vorburger.ch](https://github.com/vorburger/ch.vorburger.exec) - launch external processes, with significant improvements over Apache Commons Exec.
 - [Exec by ZT](https://github.com/zeroturnaround/zt-exec) - another external process utility
 - [Logging](https://en.wikipedia.org/wiki/Apache_Commons_Logging) Wrapper around a variety of logging API implementations.