added missing escape

git-svn-id: https://svn.macports.org/repository/macports/trunk/dports@3849 d073be05-634f-4543-b044-5fe20cf6d1d6

math/gsl/Portfile

@@ -1,4 +1,4 @@
-# $Id: Portfile,v 1.3 2003/10/29 13:12:50 michaelm Exp $
+# $Id: Portfile,v 1.4 2003/10/29 17:57:06 michaelm Exp $
 
 PortSystem 1.0
 
@@ -14,7 +14,7 @@ configure.args		--mandir='${prefix}/share/man'
 
 long_description	The GNU Scientific Library (GSL) is a numerical \
 library for C and C++ programmers.  It is free software under the GNU \
-General Public License.  
+General Public License.  \
 \
 The library provides a wide range of mathematical routines such as random \
 number generators, special functions and least-squares fitting. There are \