Update TLS example in other languages (#1033)

Added TLS example in other languages, following #1013

Author: alemohamad

docs/advanced/server.de.md

@@ -132,7 +132,7 @@ Der Parameter _tlsConfiguration_ legt fest, ob TLS (SSL) verwendet werden soll.
 // Enable TLS.
 app.http.server.configuration.tlsConfiguration = .makeServerConfiguration(
     certificateChain: try NIOSSLCertificate.fromPEMFile("/path/to/cert.pem").map { .certificate($0) },
-    privateKey: .file("/path/to/key.pem")
+    privateKey: try NIOSSLPrivateKey(file: "/path/to/key.pem", format: .pem))
 )
 ```
 

docs/advanced/server.es.md

@@ -140,7 +140,7 @@ El parámetro `tlsConfiguration` controla si TLS (SSL) está habilitado en el se
 // Habilitar TLS.
 app.http.server.configuration.tlsConfiguration = .makeServerConfiguration(
     certificateChain: try NIOSSLCertificate.fromPEMFile("/path/to/cert.pem").map { .certificate($0) },
-    privateKey: .file("/path/to/key.pem")
+    privateKey: try NIOSSLPrivateKey(file: "/path/to/key.pem", format: .pem))
 )
 ```
 

docs/advanced/server.nl.md

@@ -141,7 +141,7 @@ De `tlsConfiguration` parameter regelt of TLS (SSL) is ingeschakeld op de server
 // Schakel TLS in.
 app.http.server.configuration.tlsConfiguration = .makeServerConfiguration(
     certificateChain: try NIOSSLCertificate.fromPEMFile("/path/to/cert.pem").map { .certificate($0) },
-    privateKey: .file("/path/to/key.pem")
+    privateKey: try NIOSSLPrivateKey(file: "/path/to/key.pem", format: .pem))
 )
 ```
 

docs/advanced/server.zh.md

@@ -140,7 +140,7 @@ app.http.server.configuration.supportVersions = [.two]
 // 启用 TLS.
 app.http.server.configuration.tlsConfiguration = .makeServerConfiguration(
     certificateChain: try NIOSSLCertificate.fromPEMFile("/path/to/cert.pem").map { .certificate($0) },
-    privateKey: .file("/path/to/key.pem")
+    privateKey: try NIOSSLPrivateKey(file: "/path/to/key.pem", format: .pem))
 )
 ```