Change argument to string

Author: Mariovido

dd-java-agent/instrumentation/apache-httpcore-5/src/main/java/datadog/trace/instrumentation/apachehttpcore5/IastHttpHostInstrumentation.java

@@ -37,7 +37,7 @@ public static class CtorAdvice {
     @Advice.OnMethodExit(suppress = Throwable.class)
     @Propagation
     public static void afterCtor(
-        @Advice.This final Object self, @Advice.Argument(2) final Object host) {
+        @Advice.This final Object self, @Advice.Argument(2) final String host) {
       final PropagationModule module = InstrumentationBridge.PROPAGATION;
       if (module != null) {
         module.taintObjectIfTainted(self, host);