fix typos

INSTALL.md

@@ -23,6 +23,7 @@
     vi /etc/mongodb.conf
 
         auth = true
+        noprealloc = true
         smallfiles = true
         
     vi /etc/redis/redis.conf
@@ -104,7 +105,6 @@
         
         fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
 
-
 ### Runtime
 
     apt-get install golang golang-go.tools