Dropping -Werror, as input-mirisdr contains warnings

[Outurnate]

-Werror causes the following warnings w/ some versions of mirisdr. I see that -Werror was turned on in the last two weeks, alongside the docker image. The downstream arch linux AUR package no longer builds:

[7/21] Building CXX object src/CMakeFiles/rtl_airband_base.dir/input-mirisdr.cpp.o
FAILED: src/CMakeFiles/rtl_airband_base.dir/input-mirisdr.cpp.o
/usr/bin/c++ -D_FILE_OFFSET_BITS=64 -D_POSIX_C_SOURCE=200112L -I/home/joseph/workspace/rtl/RTLSDR-Airband-5.0.6/build/src -Wall -Wextra -Wshadow -Wdate-time -Wpointer-arith -Wwrite-strings -Wcast-qual  -Wunreachable-code -Werror -O3 -DNDEBUG -std=c++11 -pthread -ffast-math -march=native -Werror -MD -MT src/CMakeFiles/rtl_airband_base.dir/input-mirisdr.cpp.o -MF src/CMakeFiles/rtl_airband_base.dir/input-mirisdr.cpp.o.d -o src/CMakeFiles/rtl_airband_base.dir/input-mirisdr.cpp.o -c /home/joseph/workspace/rtl/RTLSDR-Airband-5.0.6/src/input-mirisdr.cpp
/home/joseph/workspace/rtl/RTLSDR-Airband-5.0.6/src/input-mirisdr.cpp: In function 'int mirisdr_find_device_by_serial(const char*)':
/home/joseph/workspace/rtl/RTLSDR-Airband-5.0.6/src/input-mirisdr.cpp:72:13: error: declaration of 'device_count' shadows a global declaration [-Werror=shadow]
   72 |         int device_count;
      |             ^~~~~~~~~~~~
In file included from /home/joseph/workspace/rtl/RTLSDR-Airband-5.0.6/src/input-mirisdr.cpp:34:
/home/joseph/workspace/rtl/RTLSDR-Airband-5.0.6/src/rtl_airband.h:345:12: note: shadowed declaration is here
  345 | extern int device_count, mixer_count;
      |            ^~~~~~~~~~~~
/home/joseph/workspace/rtl/RTLSDR-Airband-5.0.6/src/input-mirisdr.cpp: In function 'int mirisdr_init(input_t*)':
/home/joseph/workspace/rtl/RTLSDR-Airband-5.0.6/src/input-mirisdr.cpp:106:44: error: cast from type 'const char*' to type 'char*' casts away qualifiers [-Werror=cast-qual]
  106 |         int r = mirisdr_set_transfer(miri, (char *)"BULK");
      |                                            ^~~~~~~~~~~~~~
/home/joseph/workspace/rtl/RTLSDR-Airband-5.0.6/src/input-mirisdr.cpp:135:45: error: cast from type 'const char*' to type 'char*' casts away qualifiers [-Werror=cast-qual]
  135 |         r = mirisdr_set_sample_format(miri, (char *)"504_S8");
      |                                             ^~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors
[20/21] Building CXX object src/CMakeFiles/rtl_airband_base.dir/config.cpp.o
ninja: build stopped: subcommand failed.

[charlie-foxtrot]

Thanks for catching this, making changes in #462 to include mirisdr in the docker container and address the warnings