http: refactor to use min of validateNumber for maxTotalSockets

Remove duplicate implementation by using min of validateNumber.

Author: deokjinkim

lib/_http_agent.js

@@ -125,10 +125,7 @@ function Agent(options) {
   validateOneOf(this.scheduling, 'scheduling', ['fifo', 'lifo']);
 
   if (this.maxTotalSockets !== undefined) {
-    validateNumber(this.maxTotalSockets, 'maxTotalSockets');
-    if (this.maxTotalSockets <= 0 || NumberIsNaN(this.maxTotalSockets))
-      throw new ERR_OUT_OF_RANGE('maxTotalSockets', '> 0',
-                                 this.maxTotalSockets);
+    validateNumber(this.maxTotalSockets, 'maxTotalSockets', 1);
   } else {
     this.maxTotalSockets = Infinity;
   }

test/parallel/test-http-agent-maxtotalsockets.js

@@ -20,8 +20,6 @@ assert.throws(() => new http.Agent({
   }), {
     code: 'ERR_OUT_OF_RANGE',
     name: 'RangeError',
-    message: 'The value of "maxTotalSockets" is out of range. ' +
-      `It must be > 0. Received ${item}`,
   });
 });