Add detection for Haiku in configure script

Patch taken from downstream:
https://github.com/haikuports/haikuports/blob/master/net-p2p/qbittorrent/patches/qbittorrent-4.3.1.patchset

configure

@@ -5224,6 +5224,18 @@ else $as_nop
 printf "%s\n" "no" >&6; }
 fi
 
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether OS is Haiku" >&5
+printf %s "checking whether OS is Haiku... " >&6; }
+if expr "$host_os" : ".*haiku.*" > /dev/null
+then :
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+printf "%s\n" "yes" >&6; }
+      LIBS="-lnetwork $LIBS"
+else $as_nop
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
+printf "%s\n" "no" >&6; }
+fi
+
 # Require 0.23 pkg-config
 
 

configure.ac

@@ -72,6 +72,12 @@ AS_IF([expr "$host_os" : ".*darwin.*" > /dev/null],
       enable_qt_dbus=no],
       [AC_MSG_RESULT([no])])
 
+AC_MSG_CHECKING([whether OS is Haiku])
+AS_IF([expr "$host_os" : ".*haiku.*" > /dev/null],
+      [AC_MSG_RESULT([yes])
+      LIBS="-lnetwork $LIBS"],
+      [AC_MSG_RESULT([no])])
+
 # Require 0.23 pkg-config
 PKG_PROG_PKG_CONFIG([0.23])
 AS_IF([test "x$PKG_CONFIG" = "x"],