Fix client refresh

Since 87b11bd we were treating client-only refreshes of the initial
server build as if they were initial builds, and not resetting the
project context.  This meant among other things that local packages
weren't being rebuilt, which led to #5074 (but also would have led to a
whole bunch of other problems).

Fixes #5074.

tools/runners/run-app.js

@@ -443,7 +443,7 @@ _.extend(AppRunner.prototype, {
   _runOnce: function (options) {
     var self = this;
     options = options || {};
-    const firstRun = options.firstRun;
+    var firstRun = options.firstRun;
 
     Console.enableProgressDisplay(true);
 
@@ -596,6 +596,8 @@ _.extend(AppRunner.prototype, {
       return bundleResultOrRunResult.runResult;
     bundleResult = bundleResultOrRunResult.bundleResult;
 
+    firstRun = false;
+
     // Read the settings file, if any
     var settings = null;
     var settingsWatchSet = new watch.WatchSet;