typo.

git-svn-id: http://root.cern.ch/svn/root/trunk@45914 27541ba8-7e3a-0410-8455-c3a389f83636

configure

@@ -1492,11 +1492,11 @@ To reduce the output of configure by removing the trailing howto message, use:
 
    --nohowto
 
-With the flog:
+Use the flag:
 
   --fail-on-missing 
 
-Configure will fail if a component that has been explicitly enabled
+to force configure to fail if a component that has been explicitly enabled
 is missing some dependencies and can not be built.
 
 enable/disable options, prefix with either --enable- or --disable-