[librsvg: 2/3] Bump the minimum Rust version to 1.39

[Federico Mena Quintero <federico src gnome org>]

commit 5ea8c903f0e1df71a2c320f2c25693a535ae8fe9
Author: Federico Mena Quintero <federico gnome org>
Date:   Thu Jan 30 11:29:47 2020 -0600

    Bump the minimum Rust version to 1.39
    
    gtk-rs requires async/await now.

 COMPILING.md | 2 +-
 configure.ac | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/COMPILING.md b/COMPILING.md
index 392128cc..b37f7d4a 100644
--- a/COMPILING.md
+++ b/COMPILING.md
@@ -32,7 +32,7 @@ minimum version is listed here; you may use a newer version instead.
 **Compilers:**
 
 * a C compiler and `make` tool; we recommend GNU `make`.
-* rust 1.36 or later
+* rust 1.39 or later
 * cargo
 
 **Mandatory dependencies:**
diff --git a/configure.ac b/configure.ac
index 93f1747e..6fc4807c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -113,7 +113,7 @@ AS_IF(test x$RUSTC = xno,
 dnl Minimum version of rustc that we support
 dnl If you change this, please update COMPILING.md
 MINIMUM_RUST_MAJOR=1
-MINIMUM_RUST_MINOR=36
+MINIMUM_RUST_MINOR=39
 
 rust_version=`$RUSTC --version`
 version=`echo "$rust_version" | sed -e 's/^rustc //g'`