package/mpfr: replace utf-8 space by ascii character

Replace utf-8 NO-BREAK-SPACE (c2 a0) in comment line by simple
ascii space character.

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/mpfr/mpfr.hash

@@ -1,5 +1,5 @@
 # From http://lists.gnu.org/archive/html/info-gnu/2019-01/msg00019.html
 sha256 1d3be708604eae0e42d578ba93b390c2a145f17743a744d8f3f8c2ad5855a38a  mpfr-4.0.2.tar.xz
 
-# Hash for license file
+# Hash for license file
 sha256 e3a994d82e644b03a792a930f574002658412f62407f5fee083f2555c5f23118  COPYING.LESSER