Update README.md

Author: alejandrofsevilla

README.md

@@ -130,13 +130,10 @@ classDiagram
         +onReceived(int connectionId, const char * data, size_t size) : void
     }
     C_0008186492458287629887 --> C_0009297713916002777393 : -m_observer
-    C_0008186492458287629887 ()-- C_0009297713916002777393 : 
     C_0015464091438354772672 --> C_0008186492458287629887 : -m_connection
     C_0015464091438354772672 --> C_0013920056604237995185 : -m_observer
-    C_0015464091438354772672 ()-- C_0013920056604237995185 : 
     C_0002490684498279635516 o-- C_0008186492458287629887 : -m_connections
     C_0002490684498279635516 --> C_0004458731545202809661 : -m_observer
-    C_0002490684498279635516 ()-- C_0004458731545202809661 : 
     C_0009297713916002777393 <|-- C_0015464091438354772672 : 
     C_0009297713916002777393 <|-- C_0002490684498279635516 :