[build] SCons build mod_deflate w/ libm for brotli

SConstruct

@@ -280,7 +280,7 @@ env = Environment(
 
 env.Help(vars.GenerateHelpText(env))
 
-if env.subst('${CC}') is not '':
+if env.subst('${CC}') != '':
 	env['CC'] = env.subst('${CC}')
 
 env['package'] = package
@@ -507,7 +507,6 @@ if 1:
 			fail("Couldn't find libbrotlienc")
 		autoconf.env.Append(
                         CPPFLAGS = [ '-DHAVE_BROTLI_ENCODE_H', '-DHAVE_BROTLI' ],
-                        LIBS = [ 'm' ],
                 )
 
 	if env['with_dbi']:

src/SConscript

@@ -103,7 +103,7 @@ modules = {
 	'mod_auth' : { 'src' : [ 'mod_auth.c' ], 'lib' : [ env['LIBCRYPTO'] ] },
 	'mod_authn_file' : { 'src' : [ 'mod_authn_file.c' ], 'lib' : [ env['LIBCRYPT'], env['LIBCRYPTO'] ] },
 	'mod_cgi' : { 'src' : [ 'mod_cgi.c' ] },
-	'mod_deflate' : { 'src' : [ 'mod_deflate.c' ], 'lib' : [ env['LIBZ'], env['LIBBZ2'], env['LIBBROTLI'] ] },
+	'mod_deflate' : { 'src' : [ 'mod_deflate.c' ], 'lib' : [ env['LIBZ'], env['LIBBZ2'], env['LIBBROTLI'], 'm' ] },
 	'mod_dirlisting' : { 'src' : [ 'mod_dirlisting.c' ], 'lib' : [ env['LIBPCRE'] ] },
 	'mod_evasive' : { 'src' : [ 'mod_evasive.c' ] },
 	'mod_evhost' : { 'src' : [ 'mod_evhost.c' ] },