comm: Avoid QString initialization of empty string

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

src/comm/BluetoothLink.cc

@@ -390,7 +390,7 @@ void BluetoothConfiguration::setDevName(const QString &name)
 QString BluetoothConfiguration::address()
 {
 #ifdef __ios__
-    return QString("");
+    return {};
 #else
     return _device.address;
 #endif

src/comm/TCPLink.cc

@@ -263,7 +263,7 @@ static QString get_ip_address(const QString& address)
             }
         }
     }
-    return QString("");
+    return {};
 }
 
 TCPConfiguration::TCPConfiguration(const QString& name) : LinkConfiguration(name)

src/comm/UDPLink.cc

@@ -65,7 +65,7 @@ static QString get_ip_address(const QString& address)
             }
         }
     }
-    return QString("");
+    return {};
 }
 
 static bool contains_target(const QList<UDPCLient*> list, const QHostAddress& address, quint16 port)