small fix for SAGA module

Author: Giovanni Manghi

python/plugins/processing/algs/saga/description/2.1_Mosaicking.txt

@@ -6,7 +6,7 @@ ParameterMultipleInput|GRID_GRID|Grid (Optional Input)|3|True
 ParameterSelection|TYPE|Preferred data storage type|[0] 1 bit;[1] 1 byte unsigned integer;[2] 1 byte signed integer;[3] 2 byte unsigned integer;[4] 2 byte signed integer;[5] 4 byte unsigned integer;[6] 4 byte signed integer;[7] 4 byte floating point;[8] 8 byte floating point|7
 ParameterSelection|INTERPOL|Interpolation|[0] Nearest Neighbor;[1] Bilinear Interpolation;[2] Inverse Distance Interpolation;[3] Bicubic Spline Interpolation;[4] B-Spline Interpolation|0
 ParameterSelection|OVERLAP|Overlapping Areas|[0] first;[1] last;[2] minimum;[3] maximum;[4] mean;[5] blend boundary;[6] feathering|1
-ParameterNumber|BLEND_DIST|Blending Distance|0.000000|999999.000000|10.000000
+ParameterNumber|BLEND_DIST|Blending Distance|0.0|None|10.0
 ParameterSelection|MATCH|Match|[0] none;[1] regression|0
 ParameterSelection|TARGET|Target Grid|[0] user defined;[1] existing grid or grid system|0
 ParameterSelection|USER_FIT|Fit|[0] nodes;[1] cells|0