minor typo fix (is is -> it is)

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@1833 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter05/bash-exp.xml

@@ -37,10 +37,9 @@ possible) as the original Bourne shell.</para>
 <para>The <userinput>&amp;&amp;</userinput>'s at the end of every line cause 
 the next command to be executed only if the previous command exists 
 with a return value of 0 indicating success. In case all of these 
-commands are copy&amp;pasted 
-on the shell, is is important to be ensured that if 
-./configure fails, make isn't being executed and, likewise, if make fails, 
-that make install isn't being executed, and so forth.</para>
+commands are copy&amp;pasted on the shell, it is important to be ensured
+that if ./configure fails, make isn't being executed and, likewise, if make
+fails, that make install isn't being executed, and so forth.</para>
 
 </sect2>