Do not require dtproj.user file to exist if no parameters are stored there

Author: pmalecka

src/SsisBuild.Core/ProjectManagement/Project.cs

@@ -318,9 +318,9 @@ public void LoadFromDtproj(string filePath, string configurationName, string pas
 
             var userConfigurationFilePath = $"{filePath}.user";
             var userConfiguration = new UserConfiguration(configurationName);
-            userConfiguration.Initialize(userConfigurationFilePath, password);
             if (File.Exists(userConfigurationFilePath))
             {
+                userConfiguration.Initialize(userConfigurationFilePath, password);
                 foreach (var userConfigurationParameter in userConfiguration.Parameters)
                 {
                     UpdateParameter(userConfigurationParameter.Key, null, ParameterSource.Configuration);