More float fixes [skip ci]

common/repositories/horses_repository.h

@@ -31,7 +31,7 @@ public:
 		int16       race;
 		int8        gender;
 		int8        texture;
-		std::string mountspeed;
+		float       mountspeed;
 		std::string notes;
 	};
 

common/repositories/items_repository.h

@@ -134,7 +134,7 @@ public:
 		int         reclevel;
 		int         recskill;
 		int         reqlevel;
-		std::string sellrate;
+		float       sellrate;
 		int         shielding;
 		int         size;
 		int         skillmodtype;