Plugin installation is broken on Raspberry Pi (FFP7.5)

[zaicik]

The install_librtmidi.sh script is broken (I think during recent FFP8 development, if I understand how the "blame" thing on GitHut works 😅 )

Symptoms
Here's the install log:

Get:1 http://mirrors.ircam.fr/pub/raspbian/raspbian bullseye/main armhf librtmidi-dev armhf 4.0.0-1 [39.3 kB]
Fetched 39.3 kB in 1s (59.5 kB/s)
dpkg-deb: building package 'librtmidi-dev' in './librtmidi-dev.deb'.
Reading package lists...
Building dependency tree...
Reading state information...
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 librtmidi-dev : Depends: librtmidi6 but it is not installable
E: Unable to correct problems, you have held broken packages.
librtmidi-dev was already set on hold.
ccache g++ -fpch-preprocess -O3 -Wno-psabi -pipe -I /opt/fpp/src -fpic -DPLATFORM_PI -I. -std=gnu++2a  -c src/FPPMIDI.cpp -o src/FPPMIDI.o
src/FPPMIDI.cpp:22:10: fatal error: rtmidi/RtMidi.h: No such file or directory
   22 | #include <rtmidi/RtMidi.h>
      |          ^~~~~~~~~~~~~~~~~
compilation terminated.
make: *** [Makefile:25: src/FPPMIDI.o] Error 1
{"Status":"Error","Message":"Could not properly install plugin"}

Proposed Fix

I think the problem lies in line 24:
elif (( DEBVER < 11 )); then
which instead should be :
elif (( DEBVER < 12 )); then

While we're here

I also noticed that sed on line 20 isn't doing what it's supposed to do
sed -i -e "s/Version\(.*\)+\(.*\)/Version\1~fpp/g" deb/DEBIAN/control
should probably be just
sed -i -e "s/Version\(.*\)/Version\1~fpp/g" deb/DEBIAN/control

Cheers !