Apply suggestions from code review

Author: edmocosta

src/main/java/org/logstash/plugins/inputs/http/util/SslSimpleBuilder.java

@@ -189,7 +189,7 @@ public SslSimpleBuilder setTrustStore(String trustStoreType, String trustStoreFi
         );
 
         if (!hasTrustStoreEntry(this.trustStore)) {
-            logger.warn("The provided Trust Store file does not contains any trusted certificate entry: {}. Please confirm this is the correct certificate and the password is correct", trustStoreFile);
+            throw new IllegalArgumentException(String.format("The provided Trust Store file does not contains any trusted certificate entry: %s", trustStoreFile));
         }
 
         return this;

src/test/java/org/logstash/plugins/inputs/http/util/SslSimpleBuilderTest.java

@@ -211,6 +211,15 @@ void testSetTrustStoreWithNullTrustStoreType() throws Exception {
         assertEquals(TRUSTSTORE_TYPE, sslSimpleBuilder.getTrustStore().getType());
     }
 
+    @Test
+    void testSetTrustStoreWithNoTrustedCertificate() {
+        assertThrows(
+                IllegalArgumentException.class,
+                () -> createPemSslSimpleBuilder().setTrustStore(KEYSTORE_TYPE, KEYSTORE, KEYSTORE_PASSWORD),
+                String.format("The provided Trust Store file does not contains any trusted certificate entry: %s", KEYSTORE)
+        );
+    }
+
     @Test
     void testDefaultVerifyModeIsNone() {
         final SslSimpleBuilder sslSimpleBuilder = createPemSslSimpleBuilder();