Don't require users of src/port/gettimeofday.c to initialize it.

Commit 8001fe67a3 introduced this
requirement, but per discussion, we want to avoid requirements of
this type to make things easier on the calling code.  An especially
important consideration is that this may be used in frontend code,
not just the backend.

Asif Naeem, reviewed by Michael Paquier

src/backend/main/main.c

@@ -261,12 +261,6 @@ startup_hacks(const char *progname)
 
 		/* In case of general protection fault, don't show GUI popup box */
 		SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX);
-
-#ifndef HAVE_GETTIMEOFDAY
-		/* Figure out which syscall to use to capture timestamp information */
-		init_win32_gettimeofday();
-#endif
-
 	}
 #endif   /* WIN32 */