remove redundant code

Author: AleksandrRogov

lib/requests/helpers/parseResponse.js

@@ -138,8 +138,6 @@ function parseBatchHeaders(text) {
 		}
 	} while (line && parts);
 
-	normalizeHeaders(headers);
-
 	return headers;
 }
 
@@ -165,46 +163,6 @@ function readTo(text, ctx, str) {
 	return text.substring(start, end);
 }
 
-function normalizeHeaders(headers) {
-	var keys = [];
-	for (var i = 0; i < headers.length; ++i) {
-		var key = normalizeHeader(headers[i]);
-		if (key.length > 0) {
-			keys.push(key);
-		}
-	}
-	return keys;
-}
-
-function normalizeHeader(header) {
-	var key = "";
-	var upperCase = false;
-	for (var i = 0; i < header.length; ++i) {
-		var letter = header[i];
-		if (letter === " " && key.length > 0) {
-			upperCase = true;
-			continue;
-		}
-		if (!isAlnum(letter)) {
-			continue;
-		}
-		if (key.length === 0 && isDigit(letter)) {
-			continue;
-		}
-		if (upperCase) {
-			upperCase = false;
-			key += letter.toUpperCase();
-		} else {
-			key += letter.toLowerCase();
-		}
-	}
-	return key;
-}
-
-function isDigit(char) {
-	return char >= "0" && char <= "9";
-}
-
 //partially taken from https://github.com/emiltholin/google-api-batch-utils
 /**
  *