! Fix syntax of script (#1469)

Author: PikachuEXE

scripts/build_ngx_pagespeed.sh

@@ -635,9 +635,9 @@ Not deleting $directory; name is suspiciously short.  Something is wrong."
       PSOL_BINARY="$MOD_PAGESPEED_DIR/out/$BUILD_TYPE/pagespeed_automatic.a"
     else
       if "$DO_DEPS_CHECK"; then
-        skip_deps_arg = ""
+        skip_deps_arg=""
       else
-        skip_deps_arg = "--skip_deps"
+        skip_deps_arg="--skip_deps"
       fi
 
       run install/build_psol.sh --skip_tests --skip_packaging "$skip_deps_arg"