imcforecast.m: Make code robust to 1 period

When using 1 period, the second dimension was a singleton that was removed as well by squeeze, resulting in a column vector when a row vector/matrix was expected. Fixes https://forum.dynare.org/t/problem-with-the-conditional-forecast-in-dynare-4-5-7/14385/2

matlab/imcforecast.m

@@ -265,13 +265,21 @@ forecasts.instruments = options_cond_fcst.controlled_varexo;
 
 for i = 1:EndoSize
     forecasts.cond.Mean.(M_.endo_names{oo_.dr.order_var(i)}) = mFORCS1(i,:)';
-    tmp = sort(squeeze(FORCS1(i,:,:))');
+    if size(FORCS1,2)>1
+        tmp = sort(squeeze(FORCS1(i,:,:))');
+    else
+        tmp = sort(squeeze(FORCS1(i,:,:)));        
+    end
     forecasts.cond.ci.(M_.endo_names{oo_.dr.order_var(i)}) = [tmp(t1,:)' ,tmp(t2,:)' ]';
 end
 
 for i = 1:n1
     forecasts.controlled_exo_variables.Mean.(options_cond_fcst.controlled_varexo{i}) = mFORCS1_shocks(i,:)';
-    tmp = sort(squeeze(FORCS1_shocks(i,:,:))');
+    if size(FORCS1_shocks,2)>1
+        tmp = sort(squeeze(FORCS1_shocks(i,:,:))');
+    else
+        tmp = sort(squeeze(FORCS1_shocks(i,:,:)));        
+    end
     forecasts.controlled_exo_variables.ci.(options_cond_fcst.controlled_varexo{i}) = [tmp(t1,:)' ,tmp(t2,:)' ]';
 end
 
@@ -290,7 +298,11 @@ mFORCS2 = mean(FORCS2,3);
 
 for i = 1:EndoSize
     forecasts.uncond.Mean.(M_.endo_names{oo_.dr.order_var(i)})= mFORCS2(i,:)';
-    tmp = sort(squeeze(FORCS2(i,:,:))');
+    if size(FORCS2,2)>1
+        tmp = sort(squeeze(FORCS2(i,:,:))');
+    else
+        tmp = sort(squeeze(FORCS2(i,:,:)));
+    end
     forecasts.uncond.ci.(M_.endo_names{oo_.dr.order_var(i)}) = [tmp(t1,:)' ,tmp(t2,:)' ]';
 end
 forecasts.graph.title = graph_title;