qemu: Update glib to build on newer gcc

Update the glib version to 2.48.2 in order to fix build failure on newer
gcc[0].

Force internal version of libpcre for glib, since otherwise the build
failed, presumably since libpcre is not provided as a module (maybe it
should?).

Increasing the glib version further to the current latest was not
tested.

[0]
  CC       libglib_2_0_la-gdate.lo
../../glib-2.39.3/glib/gdate.c: In function 'g_date_strftime':
../../glib-2.39.3/glib/gdate.c:2497:7: error: format not a string literal, format string not checked [-Werror=format-nonliteral]
       tmplen = strftime (tmpbuf, tmpbufsize, locale_format, &tm);
       ^~~~~~

source-builder/config/glib-2-1.cfg

@@ -59,7 +59,8 @@ URL: 	   https://developer.gnome.org/glib/
     --datadir=%{_datadir} \
     --build=%{_build} --host=%{_host} \
     --with-sysroot=$SYSROOT \
-    --disable-dtrace
+    --disable-dtrace \
+    --with-pcre=internal
 
   %{_ld_library_path}=$SYSROOT/lib \
   %{__make} %{?_smp_mflags} all