ma-chat: Don't warn if room name not found

It's common and valid to not have name for a room,
So don't warn in that cases
7 jobs for wip/sadiq/matrix-fixes in 8 minutes and 30 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Build
passed build-pureos-gcc-byzantium #373115
librem5

00:01:48

 
  Test
passed check-po #373117
librem5

00:00:19

passed test:debian-gcc #373116
librem5

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21.1%
 
  Package
passed package-pureos-byzantium #373118
librem5

00:01:41

passed package-pureos-byzantium:arm64 #373119
librem5:arm64

00:05:05

 
  Test Package
passed autopkgtest-pureos-byzantium-package #373120
librem5

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passed lintian-pureos-byzantium-package #373121
librem5

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