fhemweb_readingsGroup.js: fix informIds from devName-readingName to rgName-devName.readingName
fhemweb_readingsGroup.js: fix informIds from devName-readingName to rgName-devName.readingNameView Changes
Source: fhemweb_readingsGroup.js: fix informIds from devName-readingName to rgName-devName.readingName (http://sourceforge.net/p/fhem/code/7533/)