Add milliseconds to soTimeout property Javadocs

Connection timeout's unit is specified as `seconds` in the annotation, but `soTimeout` unit is not specified as `milliseconds`, so people who do not know the parameter information of the java socket library may be confused.

spring-integration-ip/src/main/java/org/springframework/integration/ip/CommonSocketOptions.java

@@ -23,7 +23,7 @@ package org.springframework.integration.ip;
 public interface CommonSocketOptions {
 
 	/**
-	 * @param soTimeout The timeout.
+	 * @param soTimeout The timeout, in milliseconds.
 	 * @see java.net.Socket#setSoTimeout(int)
 	 * @see java.net.DatagramSocket#setSoTimeout(int)
 	 */

spring-integration-ip/src/main/java/org/springframework/integration/ip/config/TcpConnectionFactoryFactoryBean.java

@@ -305,7 +305,7 @@ public class TcpConnectionFactoryFactoryBean extends AbstractFactoryBean<Abstrac
 	}
 
 	/**
-	 * @param soTimeout The timeout.
+	 * @param soTimeout The timeout, in milliseconds.
 	 * @see AbstractConnectionFactory#setSoTimeout(int)
 	 */
 	public void setSoTimeout(int soTimeout) {

spring-integration-ip/src/main/java/org/springframework/integration/ip/dsl/AbstractConnectionFactorySpec.java

@@ -53,7 +53,7 @@ public abstract class AbstractConnectionFactorySpec
 	}
 
 	/**
-	 * @param soTimeout the timeout socket option.
+	 * @param soTimeout the timeout socket option, in milliseconds.
 	 * @return the spec.
 	 * @see AbstractConnectionFactory#setSoTimeout(int)
 	 */

spring-integration-ip/src/main/java/org/springframework/integration/ip/dsl/UdpInboundChannelAdapterSpec.java

@@ -45,7 +45,7 @@ public class UdpInboundChannelAdapterSpec
 	}
 
 	/**
-	 * @param soTimeout set the timeout socket option.
+	 * @param soTimeout set the timeout socket option, in milliseconds.
 	 * @return the spec.
 	 * @see UnicastReceivingChannelAdapter#setSoTimeout(int)
 	 */

spring-integration-ip/src/main/java/org/springframework/integration/ip/tcp/connection/AbstractConnectionFactory.java

@@ -198,7 +198,7 @@ public abstract class AbstractConnectionFactory extends IntegrationObjectSupport
 	}
 
 	/**
-	 * @param soTimeout the soTimeout to set
+	 * @param soTimeout the soTimeout to set, in milliseconds
 	 */
 	public void setSoTimeout(int soTimeout) {
 		this.soTimeout = soTimeout;