update links in README
update links in README

bonashen/ChatSecureAndroid,kden/ChatSecureAndroid,anvayarai/my-ChatSecure,kden/ChatSecureAndroid,joskarthic/chatsecure,n8fr8/ChatSecureAndroid,joskarthic/chatsecure,bonashen/ChatSecureAndroid,eighthave/ChatSecureAndroid,n8fr8/AwesomeApp,kden/ChatSecureAndroid,n8fr8/ChatSecureAndroid,Heart2009/ChatSecureAndroid,Heart2009/ChatSecureAndroid,prembasumatary/ChatSecureAndroid,n8fr8/AwesomeApp,guardianproject/ChatSecureAndroid,joskarthic/chatsecure,bonashen/ChatSecureAndroid,anvayarai/my-ChatSecure,Heart2009/ChatSecureAndroid,anvayarai/my-ChatSecure,prembasumatary/ChatSecureAndroid,h2ri/ChatSecureAndroid,eighthave/ChatSecureAndroid,prembasumatary/ChatSecureAndroid,guardianproject/ChatSecureAndroid,h2ri/ChatSecureAndroid,eighthave/ChatSecureAndroid,guardianproject/ChatSecureAndroid,h2ri/ChatSecureAndroid,n8fr8/AwesomeApp,n8fr8/ChatSecureAndroid