Update sockaddr_in+Extension.swift

Author: shogo4405

SRTHaishinKit/Sources/Extension/sockaddr_in+Extension.swift

@@ -9,13 +9,17 @@ extension sockaddr_in {
         self.init()
         self.sin_family = sa_family_t(AF_INET)
         self.sin_port = CFSwapInt16BigToHost(UInt16(port))
-        guard inet_pton(AF_INET, host, &self.sin_addr) == 1 else {
-            return nil
+        if inet_pton(AF_INET, host, &sin_addr) == 1 {
+            return
         }
         guard let hostent = gethostbyname(host), hostent.pointee.h_addrtype == AF_INET else {
             return nil
         }
-        self.sin_addr = UnsafeRawPointer(hostent.pointee.h_addr_list[0]!).assumingMemoryBound(to: in_addr.self).pointee
+        if let h_addr_list = hostent.pointee.h_addr_list[0] {
+            self.sin_addr = UnsafeRawPointer(h_addr_list).assumingMemoryBound(to: in_addr.self).pointee
+        } else {
+            return nil
+        }
     }
 
     mutating func makeSockaddr() -> sockaddr {