Use gravity instead of verb

src/Protocol/DFRN.php

@@ -2310,7 +2310,7 @@ class DFRN
 			) {
 				$is_like = true;
 				$item["type"] = "activity";
-				$item["gravity"] = GRAVITY_LIKE;
+				$item["gravity"] = GRAVITY_ACTIVITY;
 				// only one like or dislike per person
 				// splitted into two queries for performance issues
 				$condition = ['uid' => $item["uid"], 'author-id' => $item["author-id"],

src/Protocol/Diaspora.php

@@ -2049,7 +2049,7 @@ class Diaspora
 
 		$datarray["type"] = "activity";
 		$datarray["verb"] = $verb;
-		$datarray["gravity"] = GRAVITY_LIKE;
+		$datarray["gravity"] = GRAVITY_ACTIVITY;
 		$datarray["parent-uri"] = $parent_item["uri"];
 
 		$datarray["object-type"] = ACTIVITY_OBJ_NOTE;

src/Protocol/OStatus.php

@@ -451,7 +451,7 @@ class OStatus
 
 				$item["verb"] = ACTIVITY_LIKE;
 				$item["parent-uri"] = $orig_uri;
-				$item["gravity"] = GRAVITY_LIKE;
+				$item["gravity"] = GRAVITY_ACTIVITY;
 			}
 
 			// http://activitystrea.ms/schema/1.0/rsvp-yes