Fix compatibility with POSIX shell in SRM (ash)

[publicarray]

Description

Rather than using arrays I'm using the newline character for separation, it is more hacky but should still work. I still need to test if deluge works with this. I have confirmed that Cloudflared works with this change on the SRM.

Fixes #5548

Checklist

• Build rule all-supported completed successfully
• New installation of package completed successfully
• Package upgrade completed successfully (Manually install the package again)
• Package functionality was tested
• Any needed documentation is updated/created

Type of change

• Bug fix
• New Package
• Package update
• Includes small framework changes
• This change requires a documentation update (e.g. Wiki)

[publicarray]

Alternatively if this approach is too hackey we could use a token character to separate multiple SERVICE_COMMANDs e.g. :

[hgy59]

@publicarray what about the reload_inst_variables function in installer.functions? It uses declare to inject the variables from the ${INST_VARIABLES} file and might fail on SRM too. (there is a fix in #5550 to declare globally (-g))

[publicarray]

Thanks @hgy59 I'll take a look

[publicarray]

I think using export should work instead of declare -g

[hgy59]

I think using export should work instead of declare -g

@publicarray you are right. The reload_inst_variables function was introduced with the minio package. There is no need to use declare and I have redesigned this function to take the file to read variable declarations as parameter.

As I already did a redesign to allow special characters in such variables (#5430) there is a conflict that must be resolved.

Finally PR #5555 can benefit of the new function load_variables_from_file.