style: add a space before (

Author: rainingmaster

README.markdown

@@ -7246,7 +7246,7 @@ Both IP addresses and domain names can be specified as the `host` argument. In c
 
 If the nameserver returns multiple IP addresses for the host name, this method will pick up one randomly.
 
-`port` is optional and accept nil(for compatibility with host is a unix domain), and it default value is zero.
+`port` is optional and accept nil (for compatibility with host is a unix domain), and it default value is zero.
 
 In case of error, the method returns `nil` followed by a string describing the error. In case of success, the method returns `1`.
 

doc/HttpLuaModule.wiki

@@ -6133,7 +6133,7 @@ Both IP addresses and domain names can be specified as the <code>host</code> arg
 
 If the nameserver returns multiple IP addresses for the host name, this method will pick up one randomly.
 
-<code>port</code> is optional and accept nil(for compatibility with host is a unix domain), and it default value is zero.
+<code>port</code> is optional and accept nil (for compatibility with host is a unix domain), and it default value is zero.
 
 In case of error, the method returns <code>nil</code> followed by a string describing the error. In case of success, the method returns <code>1</code>.