correct typo

git-svn-id: svn://bind10.isc.org/svn/bind10/trunk@1533 e5f2f494-b856-4b98-b285-d166d9295462

doc/userguide/userguide.xml

@@ -241,7 +241,7 @@ var/
             Some operating systems have split their distribution packages into
             a run-time and a development package.  You will need to install
             the development package versions, which include header files and
-            libraries, to build BIND 10 form source code.
+            libraries, to build BIND 10 from source code.
           </para>
         </note>