build: remove specific libstrophe build check

For autotools this was added in:
75bb00368f

Regarding:
https://github.com/profanity-im/profanity/issues/1334

I think libstrophe is rather common now and should be treated
like all the other dependencies anyways.
So I'll remove this from the meson files at least. Since my
goal is to have a cleaner build system.

meson.build

@@ -83,17 +83,6 @@ thread_dep = dependency('threads')
 math_dep = cc.find_library('m', required: true)
 libstrophe_dep = dependency('libstrophe', version: '>= 0.12.3')
 
-# Check if libstrophe works
-if not cc.links('''
-  #include <strophe.h>
-  int main() {
-    xmpp_initialize();
-    return 0;
-  }
-  ''', dependencies: libstrophe_dep)
-  error('libstrophe is broken')
-endif
-
 # Check for XMPP_CERT_PUBKEY_FINGERPRINT_SHA256 support
 if cc.links('''
   #include <strophe.h>