ltrace: Add -Wno-bool-compare

Add option to ignore the following issue:

    source/ltrace-elf.c: In function 'elf_read_u16':
    source/ltrace-elf.c:221:42: error: comparison of constant '0' with boolean expression is always false [-Werror=bool-compare]
       if (!need_data(data, offset, SIZE / 8) < 0)  \
                                              ^
    source/ltrace-elf.c:238:1: note: in expansion of macro 'DEF_READER'
     DEF_READER(elf_read_u16, 16)
     ^~~~~~~~~~
    cc1: all warnings being treated as errors

ltrace.be0

@@ -52,7 +52,7 @@ SRCURL[0]="https://www.ltrace.org/ltrace_${PKGVERSION}.orig.tar.bz2"
 #}
 
 mee_build() {
-    bee_build CFLAGS='-Wno-deprecated-declarations'
+    bee_build CFLAGS='-Wno-deprecated-declarations -Wno-bool-compare'
 }
 
 #mee_install() {