Increase test robustness by adding LC_ALL=C (#1660)

Use C locale, because some tests check for English expressions

Fixes #1658

test/test-utils.sh

@@ -37,6 +37,8 @@ BIG_FILE_BLOCK_SIZE=$((25 * 1024 * 1024))
 BIG_FILE_COUNT=1
 # This should be greater than the multipart size
 BIG_FILE_LENGTH=$(($BIG_FILE_BLOCK_SIZE * $BIG_FILE_COUNT))
+# Use C locale, because some tests check for English expressions
+export LC_ALL=C
 export RUN_DIR
 
 # [NOTE]