gh-41553: fix the error message in #41502

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Follow #41502 fix the case sensetive problem.

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URL: #41553
Reported by: Chenxin Zhong
Reviewer(s):

Author: Release Manager

build/pkgs/configure/checksums.ini

@@ -1,3 +1,3 @@
 tarball=configure-VERSION.tar.gz
-sha1=b4e31848f08c83ffe0793f5b1509830a15d4b53d
-sha256=08540d0d89cdeff76ca19e08146bd0f7ae4847ce34f181a1c95a46bda90fb823
+sha1=3ee4952f26855b89bf1eeccadc7e3e132e01709d
+sha256=fcb787575354a8cdd71cd4be57e2c4c55897143c973065ae130f42747a65202e

build/pkgs/configure/package-version.txt

@@ -1 +1 @@
-fb670de31eef46a947c48d8a9cbb88a942809f52
+712d8d44be14caf75d3f21aede2ffe21823d7588

src/sage/matrix/matrix2.pyx

@@ -10678,7 +10678,7 @@ cdef class Matrix(Matrix1):
             sage: decomp = bistochastic_as_sum_of_permutations(M)                       # needs sage.graphs
             Traceback (most recent call last):
             ...
-            ValueError: The matrix is not bistochastic
+            ValueError: the matrix is not bistochastic
         """
 
         from sage.combinat.permutation import bistochastic_as_sum_of_permutations