settings-helpers: set TZ variable after changing timezone

Origin commit data
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Branch: ni/coolstream
Commit: ceadf431e6
Author: vanhofen <vanhofen@gmx.de>
Date: 2021-10-12 (Tue, 12 Oct 2021)

Origin message was:
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- settings-helpers: set TZ variable after changing timezone

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No further description and justification available within origin commit message!

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This commit was generated by Migit

src/system/setting_helpers.cpp

@@ -633,10 +633,8 @@ bool CTZChangeNotifier::changeNotify(const neutrino_locale_t, void * Data)
 			fprintf(f, "%s\n", zone.c_str());
 			fclose(f);
 		}
-#if 0
 		cmd = ":" + zone;
 		setenv("TZ", cmd.c_str(), 1);
-#endif
 		tzset();
 	}