Use text/plain instead of incorrect plain/text

Author: rsvoboda

extensions/smallrye-openapi/deployment/src/main/java/io/quarkus/smallrye/openapi/deployment/SmallRyeOpenApiProcessor.java

@@ -164,8 +164,8 @@ public class SmallRyeOpenApiProcessor {
     static {
         System.setProperty(io.smallrye.openapi.api.constants.OpenApiConstants.DEFAULT_PRODUCES, "application/json");
         System.setProperty(io.smallrye.openapi.api.constants.OpenApiConstants.DEFAULT_CONSUMES, "application/json");
-        System.setProperty(io.smallrye.openapi.api.constants.OpenApiConstants.DEFAULT_PRODUCES_PRIMITIVES, "plain/text");
-        System.setProperty(io.smallrye.openapi.api.constants.OpenApiConstants.DEFAULT_CONSUMES_PRIMITIVES, "plain/text");
+        System.setProperty(io.smallrye.openapi.api.constants.OpenApiConstants.DEFAULT_PRODUCES_PRIMITIVES, "text/plain");
+        System.setProperty(io.smallrye.openapi.api.constants.OpenApiConstants.DEFAULT_CONSUMES_PRIMITIVES, "text/plain");
     }
 
     @BuildStep

extensions/smallrye-openapi/deployment/src/test/java/io/quarkus/smallrye/openapi/test/jaxrs/DefaultContentTypeTest.java

@@ -28,7 +28,7 @@ public void testOpenApiPathAccessResource() {
                         Matchers.containsString("#/components/schemas/Greeting"))
                 .body("paths.'/greeting/hello'.get.responses.'200'.content.'application/json'.schema.$ref",
                         Matchers.containsString("#/components/schemas/Greeting"))
-                .body("paths.'/greeting/foo'.get.responses.'200'.content.'plain/text'.schema.type",
+                .body("paths.'/greeting/foo'.get.responses.'200'.content.'text/plain'.schema.type",
                         Matchers.equalTo("string"))
                 .body("paths.'/greeting/hello'.post.responses.'200'.content.'application/json'.schema.$ref",
                         Matchers.containsString("#/components/schemas/Greeting"));

integration-tests/main/src/test/java/io/quarkus/it/main/OpenApiTestCase.java

@@ -22,7 +22,7 @@
 public class OpenApiTestCase {
 
     private static final String DEFAULT_MEDIA_TYPE = "application/json";
-    private static final String DEFAULT_MEDIA_TYPE_PRIMITAVE = "plain/text";
+    private static final String DEFAULT_MEDIA_TYPE_PRIMITAVE = "text/plain";
 
     @TestHTTPResource("q/openapi")
     URL uri;