Fix double quoting of pkg-config when package contains a space

Example: Pkg_config.query p ~package:"gtk+-3.0 >= 3.10"

Fixes ocaml#1833

Signed-off-by: Christophe Troestler <Christophe.Troestler@umons.ac.be>

src/configurator/v1.ml

@@ -152,8 +152,8 @@ module Process = struct
   let command_line prog args =
     String.concat ~sep:" " (List.map (prog :: args) ~f:quote_if_needed)
 
-(* [cmd] which cannot be quoted (such as [t.c_compiler] which contains
-   some flags) followed by additional arguments. *)
+  (* [cmd] which cannot be quoted (such as [t.c_compiler] which contains
+     some flags) followed by additional arguments. *)
   let command_args cmd args =
     String.concat ~sep:" " (cmd :: List.map args ~f:quote_if_needed)
 
@@ -510,8 +510,6 @@ module Pkg_config = struct
     }
 
   let query t ~package =
-    let package = quote_if_needed package in
-    let pkg_config = quote_if_needed t.pkg_config in
     let c = t.configurator in
     let dir = c.dest_dir in
     let env =
@@ -529,10 +527,10 @@ module Pkg_config = struct
         end
       | _ -> []
     in
-    if Process.run_ok c ~dir ~env pkg_config [package] then
+    if Process.run_ok c ~dir ~env t.pkg_config [package] then
       let run what =
-        match String.trim
-                (Process.run_capture_exn c ~dir ~env pkg_config [what; package])
+        match String.trim (Process.run_capture_exn c ~dir ~env
+                             t.pkg_config [what; package])
         with
         | "" -> []
         | s  -> String.split s ~on:' '