Fixed spelling

Author: vkholodkov

Changelog

@@ -5,7 +5,7 @@ Version 2.0.4
  * Added feature: directive upload_aggregate_form_field to pass aggragate properties
    of a file like file size, MD5 and SHA1 sums to backend.
  * Fixed bug: missing CRLF at the end of resulting body.
- * Change: optimized out some unnecessary memory allocations and zeroeing.
+ * Change: optimized out some unnecessary memory allocations and zeroing.
 
 Version 2.0.3
  * upload_store directive was not able to receive more than one argument.