Redirect cubic to spline when loading alsoft.ini (#1018)

* Redirect the old cubic ini option to spline, as that's the comparable type

* Fix tabbing

* Fix if statement spacing

core/voice.cpp

@@ -148,8 +148,13 @@ void Voice::InitMixer(std::optional<std::string> resopt)
         };
 
         std::string_view resampler{*resopt};
-        if(al::case_compare(resampler, "cubic"sv) == 0
-            || al::case_compare(resampler, "sinc4"sv) == 0
+
+        if (al::case_compare(resampler, "cubic"sv) == 0)
+        {
+            WARN("Resampler option \"%s\" is deprecated, using spline\n", resopt->c_str());
+            resampler = "spline"sv;
+        }
+        else if(al::case_compare(resampler, "sinc4"sv) == 0
             || al::case_compare(resampler, "sinc8"sv) == 0)
         {
             WARN("Resampler option \"%s\" is deprecated, using gaussian\n", resopt->c_str());