fix database reference Bug: 28699830
fix database reference
Bug: 28699830

Change-Id: Idc523406658de848cdaee9723ba9ba7b6edb7add

OopsMouse/friendlychat,RNT17/FriendlyChat-Android-Codelab,letrungkien0210/friendlychat,CH34MKE10/firebase_friendly_chat,RNT17/FriendlyChat-Android-Codelab,Daniiel323/Prueba-,vlrichard00/HomeworkSix,Negi4A/minechat,vlrichard00/HomeworkSix,Franz08/Firebase-chat,mBeierl/friendlychat,letrungkien0210/friendlychat,Franz08/Firebase-chat,jemmel20/Firebase-Chat,jemmel20/Firebase-Chat,vlrichard00/HomeworkSix,Daniiel323/Prueba-,vlrichard00/HomeworkSix,mBeierl/friendlychat,firebase/codelab-friendlychat-web,roberrera/FriendlyChat,RNT17/FriendlyChat-Android-Codelab,CH34MKE10/firebase_friendly_chat,Franz08/Firebase-chat,Negi4A/minechat,CH34MKE10/firebase_friendly_chat,CH34MKE10/firebase_friendly_chat,Franz08/Firebase-chat,vlrichard00/HomeworkSix,RNT17/FriendlyChat-Android-Codelab,mBeierl/friendlychat,firebase/codelab-friendlychat-web,mBeierl/friendlychat,Daniiel323/Prueba-,mBeierl/friendlychat,jemmel20/Firebase-Chat,Franz08/Firebase-chat,jemmel20/Firebase-Chat,CH34MKE10/firebase_friendly_chat,letrungkien0210/friendlychat,letrungkien0210/friendlychat,jemmel20/Firebase-Chat,Negi4A/minechat,mBeierl/friendlychat,volny/friendlychat,letrungkien0210/friendlychat,OopsMouse/friendlychat,volny/friendlychat,RNT17/FriendlyChat-Android-Codelab