Correct vim 7.4 patch requirement

README.md

@@ -524,7 +524,7 @@ process.
     it should say `Vi IMproved X.Y`, where X.Y is the major version of vim. If
     your version is greater than 7.4, then you're all set. If your version is
     7.4 then look below that where it says, `Included patches: 1-Z`, where Z
-    will be some number. That number needs to be 143 or higher.
+    will be some number. That number needs to be 1578 or higher.
 
     If your version of Vim is not recent enough, you may need to [compile Vim
     from source][vim-build] (don't worry, it's easy).

doc/youcompleteme.txt

@@ -739,7 +739,7 @@ will notify you to recompile it. You should then rerun the install process.
    output; it should say 'Vi IMproved X.Y', where X.Y is the major version
    of vim. If your version is greater than 7.4, then you're all set. If your
    version is 7.4 then look below that where it says, 'Included patches:
-   1-Z', where Z will be some number. That number needs to be 143 or higher.
+   1-Z', where Z will be some number. That number needs to be 1578 or higher.
 
    If your version of Vim is not recent enough, you may need to compile Vim
    from source [30] (don't worry, it's easy).