Solve GSOD when removing currently played radio service

WHen in radio mode the channelselection was always displayed you could get
a GSOD. Thanks Dima73 for reporting.
Commit a different fix for the GSOD in the radiomode

As the previous fix could get a GSOD when for example you are in the
movemode
httpstream: fix off-by-one error which might result in a segfault.
etpm: fix possible segfault

The indent was incorrect which concealed a block of memory
being used (returned) after been released. The pointer now
explicitly set to NULL prevents this.
Merge branch 'master' of git://git.code.sf.net/p/openpli/enigma2 into BETA