Canonicalize unknown. (#69)

diff --git a/src/plugin/plugin_pdo.rs b/src/plugin/plugin_pdo.rs
index 7cf1fa9..1f31b56 100644
--- a/src/plugin/plugin_pdo.rs
+++ b/src/plugin/plugin_pdo.rs
@@ -291,7 +291,7 @@
             "oci" => "1521", // Oracle
             "sqlsrv" => "1433",
             "pgsql" => "5432",
-            _ => "unknown",
+            _ => "0",
         };
 
         let ss = data_source.split(';');
diff --git a/src/request.rs b/src/request.rs
index ec8d0a5..c8c325b 100644
--- a/src/request.rs
+++ b/src/request.rs
@@ -116,14 +116,14 @@
                 .and_then(z_val_to_string)
                 .map(|port| format!("localhost:{}", port))
         })
-        .unwrap_or_else(|| "UNKNOWN".to_string());
+        .unwrap_or_else(|| "unknown:0".to_string());
 
     let uri = server
         .get("REQUEST_URI")
         .and_then(z_val_to_string)
         .or_else(|| server.get("PHP_SELF").and_then(z_val_to_string))
         .or_else(|| server.get("SCRIPT_NAME").and_then(z_val_to_string))
-        .unwrap_or_else(|| "/UNKNOWN".to_string());
+        .unwrap_or_else(|| "/unknown".to_string());
 
     Ok(Url::parse(&format!("{}://{}{}", scheme, addr, uri))?)
 }
@@ -256,12 +256,12 @@
                 .and_then(z_val_to_string)
                 .map(|port| format!("localhost:{}", port))
         })
-        .unwrap_or_else(|| "UNKNOWN".to_string());
+        .unwrap_or_else(|| "unknown:0".to_string());
 
     let uri = server
         .get("request_uri")
         .and_then(z_val_to_string)
-        .unwrap_or_else(|| "/UNKNOWN".to_string());
+        .unwrap_or_else(|| "/unknown".to_string());
 
     let query = server
         .get("query_string")