format: add missing headers

- add missing include headers in different part of tgbot-cpp library, remove unused includes

Tested:
- Local build

1 files changed, 1 insertions, 1 deletions

diff --git a/src/tools/StringTools.cpp b/src/tools/StringTools.cpp
index f49a78e..8b8f4da 100644
--- a/src/tools/StringTools.cpp
+++ b/src/tools/StringTools.cpp
@@ -1,9 +1,9 @@
 #include "tgbot/tools/StringTools.h"
 
-#include <cstdlib>
 #include <iomanip>
 #include <cstdio>
 #include <random>
+#include <string>
 
 using namespace std;