config_unix.h: Move pwd.h include to rtp.c which is the only place its used

Author: mpiatka

src/config_unix.h

@@ -73,7 +73,6 @@
 #include <stdint.h>
 
 #include <limits.h>
-#include <pwd.h>
 #include <signal.h>
 #include <ctype.h>
 

src/rtp/rtp.c

@@ -76,6 +76,10 @@
 #include "config_win32.h"
 #endif // defined HAVE_CONFIG_H
 
+#ifndef _WIN32
+#include <pwd.h>
+#endif
+
 #include <errno.h>
 #include <inttypes.h>
 #include <stdatomic.h>